a[i], which
- * is a[j]*(i-j). And meanwhile, all these bars (a[j]'s) are already done, and thus are
- * throwable (using pop() with a stack).
- *
- * We can use an array nLeftGeq[] of size n to simulate a stack. nLeftGeq[i] = the number
- * of elements to the left of [i] having value greater than or equal to a[i] (including a[i]
- * itself). It is also the index difference between [i] and the next index on the top of the
- * stack.
- */
- int n = heights.length;
- if (n == 0) {
- return 0;
- }
- int[] nLeftGeq = new int[n];
- // the number of elements to the left
- // of [i] with value >= heights[i]
- nLeftGeq[0] = 1;
- // preIdx=the index of stack.peek(), res=max area so far
- int preIdx = 0;
- int res = 0;
- for (int i = 1; i < n; i++) {
- nLeftGeq[i] = 1;
- // notice that preIdx = i - 1 = peek()
- while (preIdx >= 0 && heights[i] < heights[preIdx]) {
- res = Math.max(res, heights[preIdx] * (nLeftGeq[preIdx] + i - preIdx - 1));
- // pop()
- nLeftGeq[i] += nLeftGeq[preIdx];
- // peek() current top
- preIdx = preIdx - nLeftGeq[preIdx];
- }
- if (preIdx >= 0 && heights[i] == heights[preIdx]) {
- // pop()
- nLeftGeq[i] += nLeftGeq[preIdx];
- }
- // otherwise nothing to do
- preIdx = i;
- }
- // compute the rest largest rectangle areas with (indices of) bases
- // on stack
- while (preIdx >= 0 && 0 < heights[preIdx]) {
- res = Math.max(res, heights[preIdx] * (nLeftGeq[preIdx] + n - preIdx - 1));
- // peek() current top
- preIdx = preIdx - nLeftGeq[preIdx];
- }
- return res;
- }
-}
diff --git a/src.save/main/java/g0001_0100/s0086_partition_list/Solution.java b/src.save/main/java/g0001_0100/s0086_partition_list/Solution.java
deleted file mode 100644
index cd6e92b63..000000000
--- a/src.save/main/java/g0001_0100/s0086_partition_list/Solution.java
+++ /dev/null
@@ -1,38 +0,0 @@
-package g0001_0100.s0086_partition_list;
-
-// #Medium #Two_Pointers #Linked_List #2022_02_21_Time_1_ms_(59.29%)_Space_42.2_MB_(29.64%)
-
-import com_github_leetcode.ListNode;
-
-/*
- * Definition for singly-linked list.
- * public class ListNode {
- * int val;
- * ListNode next;
- * ListNode() {}
- * ListNode(int val) { this.val = val; }
- * ListNode(int val, ListNode next) { this.val = val; this.next = next; }
- * }
- */
-public class Solution {
- public ListNode partition(ListNode head, int x) {
- ListNode nHead = new ListNode(0);
- ListNode nTail = new ListNode(0);
- ListNode ptr = nTail;
- ListNode temp = nHead;
- while (head != null) {
- ListNode nNext = head.next;
- if (head.val < x) {
- nHead.next = head;
- nHead = nHead.next;
- } else {
- nTail.next = head;
- nTail = nTail.next;
- }
- head = nNext;
- }
- nTail.next = null;
- nHead.next = ptr.next;
- return temp.next;
- }
-}
diff --git a/src.save/main/java/g0001_0100/s0087_scramble_string/Solution.java b/src.save/main/java/g0001_0100/s0087_scramble_string/Solution.java
deleted file mode 100644
index d250e05d8..000000000
--- a/src.save/main/java/g0001_0100/s0087_scramble_string/Solution.java
+++ /dev/null
@@ -1,27 +0,0 @@
-package g0001_0100.s0087_scramble_string;
-
-// #Hard #String #Dynamic_Programming #2022_02_21_Time_23_ms_(54.15%)_Space_44.1_MB_(52.46%)
-
-public class Solution {
- public boolean isScramble(String s1, String s2) {
- int n = s1.length();
- boolean[][][] dp = new boolean[n][n][n + 1];
-
- for (int len = 1; len <= n; len++) {
- for (int i = 0; i <= n - len; i++) {
- for (int j = 0; j <= n - len; j++) {
- if (len == 1) {
- dp[i][j][len] = s1.charAt(i) == s2.charAt(j);
- } else {
- for (int k = 1; k < len && !dp[i][j][len]; k++) {
- dp[i][j][len] =
- (dp[i][j][k] && dp[i + k][j + k][len - k])
- || (dp[i][j + len - k][k] && dp[i + k][j][len - k]);
- }
- }
- }
- }
- }
- return dp[0][0][n];
- }
-}
diff --git a/src.save/main/java/g0001_0100/s0088_merge_sorted_array/Solution.java b/src.save/main/java/g0001_0100/s0088_merge_sorted_array/Solution.java
deleted file mode 100644
index 314545fd8..000000000
--- a/src.save/main/java/g0001_0100/s0088_merge_sorted_array/Solution.java
+++ /dev/null
@@ -1,19 +0,0 @@
-package g0001_0100.s0088_merge_sorted_array;
-
-// #Easy #Top_Interview_Questions #Array #Sorting #Two_Pointers #Data_Structure_I_Day_2_Array
-// #2022_02_21_Time_0_ms_(100.00%)_Space_43.6_MB_(6.54%)
-
-public class Solution {
- public void merge(int[] nums1, int m, int[] nums2, int n) {
- int i = m - 1;
- int j = nums1.length - 1;
- int p2 = n - 1;
- while (p2 >= 0) {
- if (i >= 0 && nums1[i] > nums2[p2]) {
- nums1[j--] = nums1[i--];
- } else {
- nums1[j--] = nums2[p2--];
- }
- }
- }
-}
diff --git a/src.save/main/java/g0001_0100/s0089_gray_code/Solution.java b/src.save/main/java/g0001_0100/s0089_gray_code/Solution.java
deleted file mode 100644
index 74ad1850a..000000000
--- a/src.save/main/java/g0001_0100/s0089_gray_code/Solution.java
+++ /dev/null
@@ -1,28 +0,0 @@
-package g0001_0100.s0089_gray_code;
-
-// #Medium #Math #Bit_Manipulation #Backtracking
-// #2022_02_21_Time_2_ms_(99.93%)_Space_47.3_MB_(80.24%)
-
-import java.util.Arrays;
-import java.util.List;
-
-public class Solution {
- public List grayCode(int n) {
- Integer[] n1 = {0};
- int shift = 1;
- while (n > 0) {
- Integer[] temp = new Integer[n1.length * 2];
- int pos = 0;
- for (Integer integer : n1) {
- temp[pos++] = integer;
- }
- for (int i = n1.length - 1; i >= 0; i--) {
- temp[pos++] = n1[i] | shift;
- }
- n1 = temp;
- shift <<= 1;
- n--;
- }
- return Arrays.asList(n1);
- }
-}
diff --git a/src.save/main/java/g0001_0100/s0090_subsets_ii/Solution.java b/src.save/main/java/g0001_0100/s0090_subsets_ii/Solution.java
deleted file mode 100644
index 07134547b..000000000
--- a/src.save/main/java/g0001_0100/s0090_subsets_ii/Solution.java
+++ /dev/null
@@ -1,38 +0,0 @@
-package g0001_0100.s0090_subsets_ii;
-
-// #Medium #Array #Bit_Manipulation #Backtracking
-// #2022_02_21_Time_2_ms_(75.68%)_Space_44.3_MB_(14.12%)
-
-import java.util.ArrayList;
-import java.util.Arrays;
-import java.util.List;
-
-@SuppressWarnings("java:S5413")
-public class Solution {
- List> allComb = new ArrayList<>();
- List comb = new ArrayList<>();
- int[] nums;
-
- public List> subsetsWithDup(int[] nums) {
- Arrays.sort(nums);
- this.nums = nums;
- dfs(0);
- allComb.add(new ArrayList<>());
- return allComb;
- }
-
- private void dfs(int start) {
- if (start > nums.length) {
- return;
- }
- for (int i = start; i < nums.length; i++) {
- if (i > start && nums[i] == nums[i - 1]) {
- continue;
- }
- comb.add(nums[i]);
- allComb.add(new ArrayList<>(comb));
- dfs(i + 1);
- comb.remove(comb.size() - 1);
- }
- }
-}
diff --git a/src.save/main/java/g0001_0100/s0091_decode_ways/Solution.java b/src.save/main/java/g0001_0100/s0091_decode_ways/Solution.java
deleted file mode 100644
index 00634d181..000000000
--- a/src.save/main/java/g0001_0100/s0091_decode_ways/Solution.java
+++ /dev/null
@@ -1,31 +0,0 @@
-package g0001_0100.s0091_decode_ways;
-
-// #Medium #Top_Interview_Questions #String #Dynamic_Programming #Dynamic_Programming_I_Day_10
-// #2022_02_21_Time_2_ms_(64.33%)_Space_42.4_MB_(18.84%)
-
-public class Solution {
- public int numDecodings(String s) {
- if (s.charAt(0) == '0') {
- return 0;
- }
- int n = s.length();
- int[] f = new int[n + 1];
- // Auxiliary
- f[0] = 1;
- f[1] = 1;
- for (int i = 2; i <= n; i++) {
- // Calculate the independent number
- if (s.charAt(i - 1) != '0') {
- // As long as the current character is not 0, it means that the previous decoding
- // number can be inherited
- f[i] = f[i - 1];
- }
- // Calculate the number of combinations
- int twodigits = (s.charAt(i - 2) - '0') * 10 + (s.charAt(i - 1) - '0');
- if (twodigits >= 10 && twodigits <= 26) {
- f[i] += f[i - 2];
- }
- }
- return f[n];
- }
-}
diff --git a/src.save/main/java/g0001_0100/s0092_reverse_linked_list_ii/Solution.java b/src.save/main/java/g0001_0100/s0092_reverse_linked_list_ii/Solution.java
deleted file mode 100644
index ab9386245..000000000
--- a/src.save/main/java/g0001_0100/s0092_reverse_linked_list_ii/Solution.java
+++ /dev/null
@@ -1,70 +0,0 @@
-package g0001_0100.s0092_reverse_linked_list_ii;
-
-// #Medium #Linked_List #2022_02_21_Time_0_ms_(100.00%)_Space_41.9_MB_(17.34%)
-
-import com_github_leetcode.ListNode;
-
-/*
- * Definition for singly-linked list.
- * public class ListNode {
- * int val;
- * ListNode next;
- * ListNode() {}
- * ListNode(int val) { this.val = val; }
- * ListNode(int val, ListNode next) { this.val = val; this.next = next; }
- * }
- */
-public class Solution {
- public ListNode reverseBetween(ListNode head, int left, int right) {
- if (left == right) {
- return head;
- }
- ListNode prev = null;
- ListNode temp = head;
- ListNode start;
- int k = left;
- while (temp != null && k > 1) {
- prev = temp;
- temp = temp.next;
- k--;
- }
- if (left > 1 && prev != null) {
- prev.next = null;
- }
- ListNode prev1 = null;
- start = temp;
- while (temp != null && right - left >= 0) {
- prev1 = temp;
- temp = temp.next;
- right--;
- }
- if (prev1 != null) {
- prev1.next = null;
- }
- if (left > 1 && prev != null) {
- prev.next = reverse(start);
- } else {
- head = reverse(start);
- prev = head;
- }
- while (prev.next != null) {
- prev = prev.next;
- }
- prev.next = temp;
- return head;
- }
-
- public ListNode reverse(ListNode head) {
- ListNode p;
- ListNode q;
- ListNode r = null;
- p = head;
- while (p != null) {
- q = p.next;
- p.next = r;
- r = p;
- p = q;
- }
- return r;
- }
-}
diff --git a/src.save/main/java/g0001_0100/s0093_restore_ip_addresses/Solution.java b/src.save/main/java/g0001_0100/s0093_restore_ip_addresses/Solution.java
deleted file mode 100644
index c66c3b030..000000000
--- a/src.save/main/java/g0001_0100/s0093_restore_ip_addresses/Solution.java
+++ /dev/null
@@ -1,42 +0,0 @@
-package g0001_0100.s0093_restore_ip_addresses;
-
-// #Medium #String #Backtracking #2022_02_21_Time_12_ms_(26.89%)_Space_43.2_MB_(22.54%)
-
-import java.util.ArrayList;
-import java.util.List;
-
-public class Solution {
- public List restoreIpAddresses(String s) {
- List results = new ArrayList<>();
- step(s, 0, new int[4], 0, results);
- return results;
- }
-
- void step(String s, int pos, int[] octets, int count, List results) {
- if (count == 4 && pos == s.length()) {
- results.add(
- String.valueOf(octets[0])
- + '.'
- + octets[1]
- + '.'
- + octets[2]
- + '.'
- + octets[3]);
- } else if (count < 4 && pos < 12) {
- int octet = 0;
- for (int i = 0; i < 3; i++) {
- if (pos + i < s.length()) {
- int digit = s.charAt(pos + i) - '0';
- octet = octet * 10 + digit;
- if (octet < 256) {
- octets[count] = octet;
- step(s, pos + i + 1, octets, count + 1, results);
- }
- if (i == 0 && digit == 0) {
- break;
- }
- }
- }
- }
- }
-}
diff --git a/src.save/main/java/g0001_0100/s0094_binary_tree_inorder_traversal/Solution.java b/src.save/main/java/g0001_0100/s0094_binary_tree_inorder_traversal/Solution.java
deleted file mode 100644
index b17281c49..000000000
--- a/src.save/main/java/g0001_0100/s0094_binary_tree_inorder_traversal/Solution.java
+++ /dev/null
@@ -1,48 +0,0 @@
-package g0001_0100.s0094_binary_tree_inorder_traversal;
-
-// #Easy #Top_100_Liked_Questions #Top_Interview_Questions #Depth_First_Search #Tree #Binary_Tree
-// #Stack #Data_Structure_I_Day_10_Tree #2022_02_21_Time_0_ms_(100.00%)_Space_42.6_MB_(5.85%)
-
-import com_github_leetcode.TreeNode;
-import java.util.ArrayList;
-import java.util.Collections;
-import java.util.List;
-
-/*
- * Definition for a binary tree node.
- * public class TreeNode {
- * int val;
- * TreeNode left;
- * TreeNode right;
- * TreeNode() {}
- * TreeNode(int val) { this.val = val; }
- * TreeNode(int val, TreeNode left, TreeNode right) {
- * this.val = val;
- * this.left = left;
- * this.right = right;
- * }
- * }
- */
-public class Solution {
- public List inorderTraversal(TreeNode root) {
- if (root == null) {
- return Collections.emptyList();
- }
- List answer = new ArrayList<>();
- inorderTraversal(root, answer);
- return answer;
- }
-
- public void inorderTraversal(TreeNode root, List answer) {
- if (root == null) {
- return;
- }
- if (root.left != null) {
- inorderTraversal(root.left, answer);
- }
- answer.add(root.val);
- if (root.right != null) {
- inorderTraversal(root.right, answer);
- }
- }
-}
diff --git a/src.save/main/java/g0001_0100/s0094_binary_tree_inorder_traversal/readme.md b/src.save/main/java/g0001_0100/s0094_binary_tree_inorder_traversal/readme.md
deleted file mode 100644
index 5068d014f..000000000
--- a/src.save/main/java/g0001_0100/s0094_binary_tree_inorder_traversal/readme.md
+++ /dev/null
@@ -1,48 +0,0 @@
-94\. Binary Tree Inorder Traversal
-
-Easy
-
-Given the `root` of a binary tree, return _the inorder traversal of its nodes' values_.
-
-**Example 1:**
-
-
-
-**Input:** root = [1,null,2,3]
-
-**Output:** [1,3,2]
-
-**Example 2:**
-
-**Input:** root = []
-
-**Output:** []
-
-**Example 3:**
-
-**Input:** root = [1]
-
-**Output:** [1]
-
-**Example 4:**
-
-
-
-**Input:** root = [1,2]
-
-**Output:** [2,1]
-
-**Example 5:**
-
-
-
-**Input:** root = [1,null,2]
-
-**Output:** [1,2]
-
-**Constraints:**
-
-* The number of nodes in the tree is in the range `[0, 100]`.
-* `-100 <= Node.val <= 100`
-
-**Follow up:** Recursive solution is trivial, could you do it iteratively?
\ No newline at end of file
diff --git a/src.save/main/java/g0001_0100/s0095_unique_binary_search_trees_ii/Solution.java b/src.save/main/java/g0001_0100/s0095_unique_binary_search_trees_ii/Solution.java
deleted file mode 100644
index 1b683e6d1..000000000
--- a/src.save/main/java/g0001_0100/s0095_unique_binary_search_trees_ii/Solution.java
+++ /dev/null
@@ -1,65 +0,0 @@
-package g0001_0100.s0095_unique_binary_search_trees_ii;
-
-// #Medium #Dynamic_Programming #Tree #Binary_Tree #Backtracking #Binary_Search_Tree
-// #2022_02_21_Time_1_ms_(97.38%)_Space_45.8_MB_(24.93%)
-
-import com_github_leetcode.TreeNode;
-import java.util.ArrayList;
-import java.util.List;
-
-/*
- * Definition for a binary tree node.
- * public class TreeNode {
- * int val;
- * TreeNode left;
- * TreeNode right;
- * TreeNode() {}
- * TreeNode(int val) { this.val = val; }
- * TreeNode(int val, TreeNode left, TreeNode right) {
- * this.val = val;
- * this.left = left;
- * this.right = right;
- * }
- * }
- */
-public class Solution {
- public List generateTrees(int n) {
- List result = new ArrayList<>();
- result.add(new TreeNode(1));
- for (int i = 2; i <= n; i++) {
- List nresult = new ArrayList<>();
- for (TreeNode r : result) {
- TreeNode node = new TreeNode(i, r, null);
- nresult.add(node);
-
- TreeNode previous = r;
- while (previous != null) {
- node = new TreeNode(i);
- TreeNode cr = copy(r);
- insert(cr, node, previous);
- previous = node.left;
- nresult.add(cr);
- }
- }
- result = nresult;
- }
- return result;
- }
-
- private void insert(TreeNode dest, TreeNode n, TreeNode from) {
- if (dest.val == from.val) {
- TreeNode h = dest.right;
- dest.right = n;
- n.left = h;
- return;
- }
- insert(dest.right, n, from);
- }
-
- private TreeNode copy(TreeNode n) {
- if (n == null) {
- return null;
- }
- return new TreeNode(n.val, copy(n.left), copy(n.right));
- }
-}
diff --git a/src.save/main/java/g0001_0100/s0096_unique_binary_search_trees/Solution.java b/src.save/main/java/g0001_0100/s0096_unique_binary_search_trees/Solution.java
deleted file mode 100644
index 2bacebe3a..000000000
--- a/src.save/main/java/g0001_0100/s0096_unique_binary_search_trees/Solution.java
+++ /dev/null
@@ -1,17 +0,0 @@
-package g0001_0100.s0096_unique_binary_search_trees;
-
-// #Medium #Top_100_Liked_Questions #Dynamic_Programming #Math #Tree #Binary_Tree
-// #Binary_Search_Tree #Dynamic_Programming_I_Day_11
-// #2022_02_21_Time_0_ms_(100.00%)_Space_41.5_MB_(6.36%)
-
-public class Solution {
- public int numTrees(int n) {
- long result = 1;
- for (int i = 0; i < n; i++) {
- result *= 2L * n - i;
- result /= i + 1;
- }
- result /= n + 1;
- return (int) result;
- }
-}
diff --git a/src.save/main/java/g0001_0100/s0096_unique_binary_search_trees/readme.md b/src.save/main/java/g0001_0100/s0096_unique_binary_search_trees/readme.md
deleted file mode 100644
index de6a28687..000000000
--- a/src.save/main/java/g0001_0100/s0096_unique_binary_search_trees/readme.md
+++ /dev/null
@@ -1,23 +0,0 @@
-96\. Unique Binary Search Trees
-
-Medium
-
-Given an integer `n`, return _the number of structurally unique **BST'**s (binary search trees) which has exactly_ `n` _nodes of unique values from_ `1` _to_ `n`.
-
-**Example 1:**
-
-
-
-**Input:** n = 3
-
-**Output:** 5
-
-**Example 2:**
-
-**Input:** n = 1
-
-**Output:** 1
-
-**Constraints:**
-
-* `1 <= n <= 19`
\ No newline at end of file
diff --git a/src.save/main/java/g0001_0100/s0097_interleaving_string/Solution.java b/src.save/main/java/g0001_0100/s0097_interleaving_string/Solution.java
deleted file mode 100644
index ef483d7dc..000000000
--- a/src.save/main/java/g0001_0100/s0097_interleaving_string/Solution.java
+++ /dev/null
@@ -1,32 +0,0 @@
-package g0001_0100.s0097_interleaving_string;
-
-// #Medium #String #Dynamic_Programming #2022_02_21_Time_1_ms_(96.15%)_Space_42.4_MB_(24.98%)
-
-public class Solution {
- public boolean isInterleave(String s1, String s2, String s3) {
- if (s3.length() != (s1.length() + s2.length())) {
- return false;
- }
- Boolean[][] cache = new Boolean[s1.length() + 1][s2.length() + 1];
- return isInterleave(s1, s2, s3, 0, 0, 0, cache);
- }
-
- public boolean isInterleave(
- String s1, String s2, String s3, int i1, int i2, int i3, Boolean[][] cache) {
- if (cache[i1][i2] != null) {
- return cache[i1][i2];
- }
- if (i1 == s1.length() && i2 == s2.length() && i3 == s3.length()) {
- return true;
- }
- boolean result = false;
- if (i1 < s1.length() && s1.charAt(i1) == s3.charAt(i3)) {
- result = isInterleave(s1, s2, s3, i1 + 1, i2, i3 + 1, cache);
- }
- if (i2 < s2.length() && s2.charAt(i2) == s3.charAt(i3)) {
- result = result || isInterleave(s1, s2, s3, i1, i2 + 1, i3 + 1, cache);
- }
- cache[i1][i2] = result;
- return result;
- }
-}
diff --git a/src.save/main/java/g0001_0100/s0098_validate_binary_search_tree/Solution.java b/src.save/main/java/g0001_0100/s0098_validate_binary_search_tree/Solution.java
deleted file mode 100644
index 957cd93f7..000000000
--- a/src.save/main/java/g0001_0100/s0098_validate_binary_search_tree/Solution.java
+++ /dev/null
@@ -1,40 +0,0 @@
-package g0001_0100.s0098_validate_binary_search_tree;
-
-// #Medium #Top_100_Liked_Questions #Top_Interview_Questions #Depth_First_Search #Tree #Binary_Tree
-// #Binary_Search_Tree #Data_Structure_I_Day_14_Tree
-// #2022_02_21_Time_0_ms_(100.00%)_Space_44.6_MB_(6.00%)
-
-import com_github_leetcode.TreeNode;
-
-/*
- * Definition for a binary tree node.
- * public class TreeNode {
- * int val;
- * TreeNode left;
- * TreeNode right;
- * TreeNode() {}
- * TreeNode(int val) { this.val = val; }
- * TreeNode(int val, TreeNode left, TreeNode right) {
- * this.val = val;
- * this.left = left;
- * this.right = right;
- * }
- * }
- */
-public class Solution {
- public boolean isValidBST(TreeNode root) {
- return solve(root, Long.MIN_VALUE, Long.MAX_VALUE);
- }
-
- // we will send a valid range and check whether the root lies in the range
- // and update the range for the subtrees
- private boolean solve(TreeNode root, long left, long right) {
- if (root == null) {
- return true;
- }
- if (root.val <= left || root.val >= right) {
- return false;
- }
- return solve(root.left, left, root.val) && solve(root.right, root.val, right);
- }
-}
diff --git a/src.save/main/java/g0001_0100/s0098_validate_binary_search_tree/readme.md b/src.save/main/java/g0001_0100/s0098_validate_binary_search_tree/readme.md
deleted file mode 100644
index a65734a4c..000000000
--- a/src.save/main/java/g0001_0100/s0098_validate_binary_search_tree/readme.md
+++ /dev/null
@@ -1,34 +0,0 @@
-98\. Validate Binary Search Tree
-
-Medium
-
-Given the `root` of a binary tree, _determine if it is a valid binary search tree (BST)_.
-
-A **valid BST** is defined as follows:
-
-* The left subtree of a node contains only nodes with keys **less than** the node's key.
-* The right subtree of a node contains only nodes with keys **greater than** the node's key.
-* Both the left and right subtrees must also be binary search trees.
-
-**Example 1:**
-
-
-
-**Input:** root = [2,1,3]
-
-**Output:** true
-
-**Example 2:**
-
-
-
-**Input:** root = [5,1,4,null,null,3,6]
-
-**Output:** false
-
-**Explanation:** The root node's value is 5 but its right child's value is 4.
-
-**Constraints:**
-
-* The number of nodes in the tree is in the range [1, 104].
-* -231 <= Node.val <= 231 - 1
\ No newline at end of file
diff --git a/src.save/main/java/g0001_0100/s0099_recover_binary_search_tree/Solution.java b/src.save/main/java/g0001_0100/s0099_recover_binary_search_tree/Solution.java
deleted file mode 100644
index 011441051..000000000
--- a/src.save/main/java/g0001_0100/s0099_recover_binary_search_tree/Solution.java
+++ /dev/null
@@ -1,49 +0,0 @@
-package g0001_0100.s0099_recover_binary_search_tree;
-
-// #Medium #Depth_First_Search #Tree #Binary_Tree #Binary_Search_Tree
-// #2022_02_21_Time_3_ms_(71.74%)_Space_47.4_MB_(17.42%)
-
-import com_github_leetcode.TreeNode;
-
-/*
- * Definition for a binary tree node.
- * public class TreeNode {
- * int val;
- * TreeNode left;
- * TreeNode right;
- * TreeNode() {}
- * TreeNode(int val) { this.val = val; }
- * TreeNode(int val, TreeNode left, TreeNode right) {
- * this.val = val;
- * this.left = left;
- * this.right = right;
- * }
- * }
- */
-public class Solution {
- private TreeNode prev = null;
- private TreeNode first = null;
- private TreeNode second = null;
-
- public void recoverTree(TreeNode root) {
- evalSwappedNodes(root);
- int temp = first.val;
- first.val = second.val;
- second.val = temp;
- }
-
- private void evalSwappedNodes(TreeNode curr) {
- if (curr == null) {
- return;
- }
- evalSwappedNodes(curr.left);
- if (prev != null && prev.val > curr.val) {
- if (first == null) {
- first = prev;
- }
- second = curr;
- }
- prev = curr;
- evalSwappedNodes(curr.right);
- }
-}
diff --git a/src.save/main/java/g0001_0100/s0100_same_tree/Solution.java b/src.save/main/java/g0001_0100/s0100_same_tree/Solution.java
deleted file mode 100644
index da925d998..000000000
--- a/src.save/main/java/g0001_0100/s0100_same_tree/Solution.java
+++ /dev/null
@@ -1,43 +0,0 @@
-package g0001_0100.s0100_same_tree;
-
-// #Easy #Depth_First_Search #Breadth_First_Search #Tree #Binary_Tree
-// #2022_02_21_Time_0_ms_(100.00%)_Space_39.5_MB_(37.48%)
-
-import com_github_leetcode.TreeNode;
-
-/*
- * Definition for a binary tree node.
- * public class TreeNode {
- * int val;
- * TreeNode left;
- * TreeNode right;
- * TreeNode() {}
- * TreeNode(int val) { this.val = val; }
- * TreeNode(int val, TreeNode left, TreeNode right) {
- * this.val = val;
- * this.left = left;
- * this.right = right;
- * }
- * }
- */
-public class Solution {
- private boolean trav(TreeNode n, TreeNode m) {
- if (n != null && m != null) {
- if (n.val != m.val) {
- return false;
- }
- return (trav(n.left, m.left) && trav(n.right, m.right));
- } else {
- return n == null && m == null;
- }
- }
-
- public boolean isSameTree(TreeNode p, TreeNode q) {
- if (p == null && q == null) {
- return true;
- } else if (p == null || q == null) {
- return false;
- }
- return trav(p, q);
- }
-}
diff --git a/src.save/main/java/g0101_0200/s0101_symmetric_tree/Solution.java b/src.save/main/java/g0101_0200/s0101_symmetric_tree/Solution.java
deleted file mode 100644
index 64feb41f3..000000000
--- a/src.save/main/java/g0101_0200/s0101_symmetric_tree/Solution.java
+++ /dev/null
@@ -1,41 +0,0 @@
-package g0101_0200.s0101_symmetric_tree;
-
-// #Easy #Top_100_Liked_Questions #Top_Interview_Questions #Depth_First_Search #Breadth_First_Search
-// #Tree #Binary_Tree #Data_Structure_I_Day_11_Tree
-// #2022_02_21_Time_0_ms_(100.00%)_Space_40.4_MB_(34.23%)
-
-import com_github_leetcode.TreeNode;
-
-/*
- * Definition for a binary tree node.
- * public class TreeNode {
- * int val;
- * TreeNode left;
- * TreeNode right;
- * TreeNode() {}
- * TreeNode(int val) { this.val = val; }
- * TreeNode(int val, TreeNode left, TreeNode right) {
- * this.val = val;
- * this.left = left;
- * this.right = right;
- * }
- * }
- */
-public class Solution {
- public boolean isSymmetric(TreeNode root) {
- if (root == null) {
- return true;
- }
- return helper(root.left, root.right);
- }
-
- private boolean helper(TreeNode leftNode, TreeNode rightNode) {
- if (leftNode == null || rightNode == null) {
- return leftNode == null && rightNode == null;
- }
- if (leftNode.val != rightNode.val) {
- return false;
- }
- return helper(leftNode.left, rightNode.right) && helper(leftNode.right, rightNode.left);
- }
-}
diff --git a/src.save/main/java/g0101_0200/s0101_symmetric_tree/readme.md b/src.save/main/java/g0101_0200/s0101_symmetric_tree/readme.md
deleted file mode 100644
index bd978643e..000000000
--- a/src.save/main/java/g0101_0200/s0101_symmetric_tree/readme.md
+++ /dev/null
@@ -1,28 +0,0 @@
-101\. Symmetric Tree
-
-Easy
-
-Given the `root` of a binary tree, _check whether it is a mirror of itself_ (i.e., symmetric around its center).
-
-**Example 1:**
-
-
-
-**Input:** root = [1,2,2,3,4,4,3]
-
-**Output:** true
-
-**Example 2:**
-
-
-
-**Input:** root = [1,2,2,null,3,null,3]
-
-**Output:** false
-
-**Constraints:**
-
-* The number of nodes in the tree is in the range `[1, 1000]`.
-* `-100 <= Node.val <= 100`
-
-**Follow up:** Could you solve it both recursively and iteratively?
\ No newline at end of file
diff --git a/src.save/main/java/g0101_0200/s0102_binary_tree_level_order_traversal/Solution.java b/src.save/main/java/g0101_0200/s0102_binary_tree_level_order_traversal/Solution.java
deleted file mode 100644
index 475555f7f..000000000
--- a/src.save/main/java/g0101_0200/s0102_binary_tree_level_order_traversal/Solution.java
+++ /dev/null
@@ -1,57 +0,0 @@
-package g0101_0200.s0102_binary_tree_level_order_traversal;
-
-// #Medium #Top_100_Liked_Questions #Top_Interview_Questions #Breadth_First_Search #Tree
-// #Binary_Tree #Data_Structure_I_Day_11_Tree #2022_02_21_Time_0_ms_(100.00%)_Space_42.4_MB_(34.08%)
-
-import com_github_leetcode.TreeNode;
-import java.util.ArrayList;
-import java.util.LinkedList;
-import java.util.List;
-import java.util.Queue;
-
-/*
- * Definition for a binary tree node.
- * public class TreeNode {
- * int val;
- * TreeNode left;
- * TreeNode right;
- * TreeNode() {}
- * TreeNode(int val) { this.val = val; }
- * TreeNode(int val, TreeNode left, TreeNode right) {
- * this.val = val;
- * this.left = left;
- * this.right = right;
- * }
- * }
- */
-public class Solution {
- public List> levelOrder(TreeNode root) {
- List> result = new ArrayList<>();
- if (root == null) {
- return result;
- }
- Queue queue = new LinkedList<>();
- queue.add(root);
- queue.add(null);
- List level = new ArrayList<>();
- while (!queue.isEmpty()) {
- root = queue.remove();
- while (!queue.isEmpty() && root != null) {
- level.add(root.val);
- if (root.left != null) {
- queue.add(root.left);
- }
- if (root.right != null) {
- queue.add(root.right);
- }
- root = queue.remove();
- }
- result.add(level);
- level = new ArrayList<>();
- if (!queue.isEmpty()) {
- queue.add(null);
- }
- }
- return result;
- }
-}
diff --git a/src.save/main/java/g0101_0200/s0102_binary_tree_level_order_traversal/readme.md b/src.save/main/java/g0101_0200/s0102_binary_tree_level_order_traversal/readme.md
deleted file mode 100644
index 92fe4a4e3..000000000
--- a/src.save/main/java/g0101_0200/s0102_binary_tree_level_order_traversal/readme.md
+++ /dev/null
@@ -1,30 +0,0 @@
-102\. Binary Tree Level Order Traversal
-
-Medium
-
-Given the `root` of a binary tree, return _the level order traversal of its nodes' values_. (i.e., from left to right, level by level).
-
-**Example 1:**
-
-
-
-**Input:** root = [3,9,20,null,null,15,7]
-
-**Output:** [[3],[9,20],[15,7]]
-
-**Example 2:**
-
-**Input:** root = [1]
-
-**Output:** [[1]]
-
-**Example 3:**
-
-**Input:** root = []
-
-**Output:** []
-
-**Constraints:**
-
-* The number of nodes in the tree is in the range `[0, 2000]`.
-* `-1000 <= Node.val <= 1000`
\ No newline at end of file
diff --git a/src.save/main/java/g0101_0200/s0103_binary_tree_zigzag_level_order_traversal/Solution.java b/src.save/main/java/g0101_0200/s0103_binary_tree_zigzag_level_order_traversal/Solution.java
deleted file mode 100644
index f5232e2f8..000000000
--- a/src.save/main/java/g0101_0200/s0103_binary_tree_zigzag_level_order_traversal/Solution.java
+++ /dev/null
@@ -1,65 +0,0 @@
-package g0101_0200.s0103_binary_tree_zigzag_level_order_traversal;
-
-// #Medium #Top_Interview_Questions #Breadth_First_Search #Tree #Binary_Tree
-// #2022_02_21_Time_1_ms_(86.98%)_Space_43.2_MB_(5.11%)
-
-import com_github_leetcode.TreeNode;
-import java.util.ArrayList;
-import java.util.LinkedList;
-import java.util.List;
-import java.util.Queue;
-
-/*
- * Definition for a binary tree node.
- * public class TreeNode {
- * int val;
- * TreeNode left;
- * TreeNode right;
- * TreeNode() {}
- * TreeNode(int val) { this.val = val; }
- * TreeNode(int val, TreeNode left, TreeNode right) {
- * this.val = val;
- * this.left = left;
- * this.right = right;
- * }
- * }
- */
-public class Solution {
- public List> zigzagLevelOrder(TreeNode root) {
- List> result = new ArrayList<>();
- if (root == null) {
- return result;
- }
- Queue q = new LinkedList<>();
- q.add(root);
- q.add(null);
- boolean zig = true;
- LinkedList level = new LinkedList<>();
- while (!q.isEmpty()) {
- TreeNode node = q.remove();
- while (!q.isEmpty() && node != null) {
- if (zig) {
- level.add(node.val);
- } else {
- level.addFirst(node.val);
- }
-
- if (node.left != null) {
- q.add(node.left);
- }
- if (node.right != null) {
- q.add(node.right);
- }
- node = q.remove();
- }
- result.add(level);
- zig = !zig;
-
- level = new LinkedList<>();
- if (!q.isEmpty()) {
- q.add(null);
- }
- }
- return result;
- }
-}
diff --git a/src.save/main/java/g0101_0200/s0104_maximum_depth_of_binary_tree/Solution.java b/src.save/main/java/g0101_0200/s0104_maximum_depth_of_binary_tree/Solution.java
deleted file mode 100644
index db706d96e..000000000
--- a/src.save/main/java/g0101_0200/s0104_maximum_depth_of_binary_tree/Solution.java
+++ /dev/null
@@ -1,37 +0,0 @@
-package g0101_0200.s0104_maximum_depth_of_binary_tree;
-
-// #Easy #Top_100_Liked_Questions #Top_Interview_Questions #Depth_First_Search #Breadth_First_Search
-// #Tree #Binary_Tree #Data_Structure_I_Day_11_Tree
-// #2022_02_21_Time_0_ms_(100.00%)_Space_43_MB_(35.64%)
-
-import com_github_leetcode.TreeNode;
-
-/*
- * Definition for a binary tree node.
- * public class TreeNode {
- * int val;
- * TreeNode left;
- * TreeNode right;
- * TreeNode() {}
- * TreeNode(int val) { this.val = val; }
- * TreeNode(int val, TreeNode left, TreeNode right) {
- * this.val = val;
- * this.left = left;
- * this.right = right;
- * }
- * }
- */
-public class Solution {
- public int maxDepth(TreeNode root) {
- return findDepth(root, 0);
- }
-
- private int findDepth(TreeNode node, int currentDepth) {
- if (node == null) {
- return 0;
- }
- currentDepth++;
- return 1
- + Math.max(findDepth(node.left, currentDepth), findDepth(node.right, currentDepth));
- }
-}
diff --git a/src.save/main/java/g0101_0200/s0104_maximum_depth_of_binary_tree/readme.md b/src.save/main/java/g0101_0200/s0104_maximum_depth_of_binary_tree/readme.md
deleted file mode 100644
index 052ac0151..000000000
--- a/src.save/main/java/g0101_0200/s0104_maximum_depth_of_binary_tree/readme.md
+++ /dev/null
@@ -1,38 +0,0 @@
-104\. Maximum Depth of Binary Tree
-
-Easy
-
-Given the `root` of a binary tree, return _its maximum depth_.
-
-A binary tree's **maximum depth** is the number of nodes along the longest path from the root node down to the farthest leaf node.
-
-**Example 1:**
-
-
-
-**Input:** root = [3,9,20,null,null,15,7]
-
-**Output:** 3
-
-**Example 2:**
-
-**Input:** root = [1,null,2]
-
-**Output:** 2
-
-**Example 3:**
-
-**Input:** root = []
-
-**Output:** 0
-
-**Example 4:**
-
-**Input:** root = [0]
-
-**Output:** 1
-
-**Constraints:**
-
-* The number of nodes in the tree is in the range [0, 104].
-* `-100 <= Node.val <= 100`
\ No newline at end of file
diff --git a/src.save/main/java/g0101_0200/s0105_construct_binary_tree_from_preorder_and_inorder_traversal/Solution.java b/src.save/main/java/g0101_0200/s0105_construct_binary_tree_from_preorder_and_inorder_traversal/Solution.java
deleted file mode 100644
index 6a93c739f..000000000
--- a/src.save/main/java/g0101_0200/s0105_construct_binary_tree_from_preorder_and_inorder_traversal/Solution.java
+++ /dev/null
@@ -1,52 +0,0 @@
-package g0101_0200.s0105_construct_binary_tree_from_preorder_and_inorder_traversal;
-
-// #Medium #Top_100_Liked_Questions #Top_Interview_Questions #Array #Hash_Table #Tree #Binary_Tree
-// #Divide_and_Conquer #2022_02_21_Time_1_ms_(99.69%)_Space_42.2_MB_(42.10%)
-
-import com_github_leetcode.TreeNode;
-import java.util.HashMap;
-import java.util.Map;
-
-/*
- * Definition for a binary tree node.
- * public class TreeNode {
- * int val;
- * TreeNode left;
- * TreeNode right;
- * TreeNode() {}
- * TreeNode(int val) { this.val = val; }
- * TreeNode(int val, TreeNode left, TreeNode right) {
- * this.val = val;
- * this.left = left;
- * this.right = right;
- * }
- * }
- */
-public class Solution {
- private int j;
- private Map map = new HashMap<>();
-
- public int get(int key) {
- return map.get(key);
- }
-
- private TreeNode answer(int[] preorder, int[] inorder, int start, int end) {
- if (start > end || j > preorder.length) {
- return null;
- }
- int value = preorder[j++];
- int index = get(value);
- TreeNode node = new TreeNode(value);
- node.left = answer(preorder, inorder, start, index - 1);
- node.right = answer(preorder, inorder, index + 1, end);
- return node;
- }
-
- public TreeNode buildTree(int[] preorder, int[] inorder) {
- j = 0;
- for (int i = 0; i < preorder.length; i++) {
- map.put(inorder[i], i);
- }
- return answer(preorder, inorder, 0, preorder.length - 1);
- }
-}
diff --git a/src.save/main/java/g0101_0200/s0105_construct_binary_tree_from_preorder_and_inorder_traversal/readme.md b/src.save/main/java/g0101_0200/s0105_construct_binary_tree_from_preorder_and_inorder_traversal/readme.md
deleted file mode 100644
index fa4a8b4dc..000000000
--- a/src.save/main/java/g0101_0200/s0105_construct_binary_tree_from_preorder_and_inorder_traversal/readme.md
+++ /dev/null
@@ -1,29 +0,0 @@
-105\. Construct Binary Tree from Preorder and Inorder Traversal
-
-Medium
-
-Given two integer arrays `preorder` and `inorder` where `preorder` is the preorder traversal of a binary tree and `inorder` is the inorder traversal of the same tree, construct and return _the binary tree_.
-
-**Example 1:**
-
-
-
-**Input:** preorder = [3,9,20,15,7], inorder = [9,3,15,20,7]
-
-**Output:** [3,9,20,null,null,15,7]
-
-**Example 2:**
-
-**Input:** preorder = [-1], inorder = [-1]
-
-**Output:** [-1]
-
-**Constraints:**
-
-* `1 <= preorder.length <= 3000`
-* `inorder.length == preorder.length`
-* `-3000 <= preorder[i], inorder[i] <= 3000`
-* `preorder` and `inorder` consist of **unique** values.
-* Each value of `inorder` also appears in `preorder`.
-* `preorder` is **guaranteed** to be the preorder traversal of the tree.
-* `inorder` is **guaranteed** to be the inorder traversal of the tree.
\ No newline at end of file
diff --git a/src.save/main/java/g0101_0200/s0106_construct_binary_tree_from_inorder_and_postorder_traversal/Solution.java b/src.save/main/java/g0101_0200/s0106_construct_binary_tree_from_inorder_and_postorder_traversal/Solution.java
deleted file mode 100644
index 07f595d26..000000000
--- a/src.save/main/java/g0101_0200/s0106_construct_binary_tree_from_inorder_and_postorder_traversal/Solution.java
+++ /dev/null
@@ -1,40 +0,0 @@
-package g0101_0200.s0106_construct_binary_tree_from_inorder_and_postorder_traversal;
-
-// #Medium #Array #Hash_Table #Tree #Binary_Tree #Divide_and_Conquer
-// #2022_02_21_Time_1_ms_(99.20%)_Space_44.6_MB_(19.25%)
-
-import com_github_leetcode.TreeNode;
-
-/*
- * Definition for a binary tree node.
- * public class TreeNode {
- * int val;
- * TreeNode left;
- * TreeNode right;
- * TreeNode() {}
- * TreeNode(int val) { this.val = val; }
- * TreeNode(int val, TreeNode left, TreeNode right) {
- * this.val = val;
- * this.left = left;
- * this.right = right;
- * }
- * }
- */
-public class Solution {
- public TreeNode buildTree(int[] inorder, int[] postorder) {
- int[] inIndex = new int[] {inorder.length - 1};
- int[] postIndex = new int[] {postorder.length - 1};
- return helper(inorder, postorder, inIndex, postIndex, Integer.MAX_VALUE);
- }
-
- private TreeNode helper(int[] in, int[] post, int[] index, int[] pIndex, int target) {
- if (index[0] < 0 || in[index[0]] == target) {
- return null;
- }
- TreeNode root = new TreeNode(post[pIndex[0]--]);
- root.right = helper(in, post, index, pIndex, root.val);
- index[0]--;
- root.left = helper(in, post, index, pIndex, target);
- return root;
- }
-}
diff --git a/src.save/main/java/g0101_0200/s0107_binary_tree_level_order_traversal_ii/Solution.java b/src.save/main/java/g0101_0200/s0107_binary_tree_level_order_traversal_ii/Solution.java
deleted file mode 100644
index 9bb58826d..000000000
--- a/src.save/main/java/g0101_0200/s0107_binary_tree_level_order_traversal_ii/Solution.java
+++ /dev/null
@@ -1,45 +0,0 @@
-package g0101_0200.s0107_binary_tree_level_order_traversal_ii;
-
-// #Medium #Breadth_First_Search #Tree #Binary_Tree
-// #2022_02_21_Time_1_ms_(93.94%)_Space_43.5_MB_(20.70%)
-
-import com_github_leetcode.TreeNode;
-import java.util.ArrayList;
-import java.util.Collections;
-import java.util.List;
-
-/*
- * Definition for a binary tree node.
- * public class TreeNode {
- * int val;
- * TreeNode left;
- * TreeNode right;
- * TreeNode() {}
- * TreeNode(int val) { this.val = val; }
- * TreeNode(int val, TreeNode left, TreeNode right) {
- * this.val = val;
- * this.left = left;
- * this.right = right;
- * }
- * }
- */
-public class Solution {
- private List> order = new ArrayList<>();
-
- public List> levelOrderBottom(TreeNode root) {
- getOrder(root, 0);
- Collections.reverse(order);
- return order;
- }
-
- public void getOrder(TreeNode root, int level) {
- if (root != null) {
- if (level + 1 > order.size()) {
- order.add(new ArrayList<>());
- }
- order.get(level).add(root.val);
- getOrder(root.left, level + 1);
- getOrder(root.right, level + 1);
- }
- }
-}
diff --git a/src.save/main/java/g0101_0200/s0108_convert_sorted_array_to_binary_search_tree/Solution.java b/src.save/main/java/g0101_0200/s0108_convert_sorted_array_to_binary_search_tree/Solution.java
deleted file mode 100644
index d28164a3a..000000000
--- a/src.save/main/java/g0101_0200/s0108_convert_sorted_array_to_binary_search_tree/Solution.java
+++ /dev/null
@@ -1,43 +0,0 @@
-package g0101_0200.s0108_convert_sorted_array_to_binary_search_tree;
-
-// #Easy #Top_Interview_Questions #Array #Tree #Binary_Tree #Binary_Search_Tree #Divide_and_Conquer
-// #2022_02_21_Time_0_ms_(100.00%)_Space_43.3_MB_(28.35%)
-
-import com_github_leetcode.TreeNode;
-
-/*
- * Definition for a binary tree node.
- * public class TreeNode {
- * int val;
- * TreeNode left;
- * TreeNode right;
- * TreeNode() {}
- * TreeNode(int val) { this.val = val; }
- * TreeNode(int val, TreeNode left, TreeNode right) {
- * this.val = val;
- * this.left = left;
- * this.right = right;
- * }
- * }
- */
-public class Solution {
- public TreeNode sortedArrayToBST(int[] num) {
- /*1. Set up recursion*/
- return makeTree(num, 0, num.length - 1);
- }
-
- private TreeNode makeTree(int[] num, int left, int right) {
- /*2. left as lowest# can't be greater than right*/
- if (left > right) {
- return null;
- }
- /*3. Set median# as node*/
- int mid = (left + right) / 2;
- TreeNode midNode = new TreeNode(num[mid]);
- /*4. Set mid node's kids*/
- midNode.left = makeTree(num, left, mid - 1);
- midNode.right = makeTree(num, mid + 1, right);
- /*5. Sends node back || Goes back to prev node*/
- return midNode;
- }
-}
diff --git a/src.save/main/java/g0101_0200/s0109_convert_sorted_list_to_binary_search_tree/Solution.java b/src.save/main/java/g0101_0200/s0109_convert_sorted_list_to_binary_search_tree/Solution.java
deleted file mode 100644
index a02bccb2d..000000000
--- a/src.save/main/java/g0101_0200/s0109_convert_sorted_list_to_binary_search_tree/Solution.java
+++ /dev/null
@@ -1,64 +0,0 @@
-package g0101_0200.s0109_convert_sorted_list_to_binary_search_tree;
-
-// #Medium #Tree #Binary_Tree #Linked_List #Binary_Search_Tree #Divide_and_Conquer
-// #2022_02_21_Time_1_ms_(80.17%)_Space_47.5_MB_(12.35%)
-
-import com_github_leetcode.ListNode;
-import com_github_leetcode.TreeNode;
-
-/*
- * Definition for singly-linked list.
- * public class ListNode {
- * int val;
- * ListNode next;
- * ListNode() {}
- * ListNode(int val) { this.val = val; }
- * ListNode(int val, ListNode next) { this.val = val; this.next = next; }
- * }
- */
-/*
- * Definition for a binary tree node.
- * public class TreeNode {
- * int val;
- * TreeNode left;
- * TreeNode right;
- * TreeNode() {}
- * TreeNode(int val) { this.val = val; }
- * TreeNode(int val, TreeNode left, TreeNode right) {
- * this.val = val;
- * this.left = left;
- * this.right = right;
- * }
- * }
- */
-public class Solution {
- public TreeNode sortedListToBST(ListNode head) {
- // Empty list -> empty tree / sub-tree
- if (head == null) {
- return null;
- }
- // No next node -> this node will become leaf
- if (head.next == null) {
- TreeNode leaf = new TreeNode(head.val);
- leaf.left = null;
- leaf.right = null;
- return leaf;
- }
- ListNode slow = head;
- // Head-Start fast by 1 to get slow = mid -1
- ListNode fast = head.next.next;
- // Find the mid of list
- while (fast != null && fast.next != null) {
- slow = slow.next;
- fast = fast.next.next;
- }
- // slow.next -> mid = our "root"
- TreeNode root = new TreeNode(slow.next.val);
- // Right sub tree from mid - end
- root.right = sortedListToBST(slow.next.next);
- // Left sub tree from head - mid (chop slow.next)
- slow.next = null;
- root.left = sortedListToBST(head);
- return root;
- }
-}
diff --git a/src.save/main/java/g0101_0200/s0110_balanced_binary_tree/Solution.java b/src.save/main/java/g0101_0200/s0110_balanced_binary_tree/Solution.java
deleted file mode 100644
index bf9928279..000000000
--- a/src.save/main/java/g0101_0200/s0110_balanced_binary_tree/Solution.java
+++ /dev/null
@@ -1,67 +0,0 @@
-package g0101_0200.s0110_balanced_binary_tree;
-
-// #Easy #Depth_First_Search #Tree #Binary_Tree
-// #2022_02_21_Time_0_ms_(100.00%)_Space_41.6_MB_(72.46%)
-
-import com_github_leetcode.TreeNode;
-
-/*
- * Definition for a binary tree node.
- * public class TreeNode {
- * int val;
- * TreeNode left;
- * TreeNode right;
- * TreeNode() {}
- * TreeNode(int val) { this.val = val; }
- * TreeNode(int val, TreeNode left, TreeNode right) {
- * this.val = val;
- * this.left = left;
- * this.right = right;
- * }
- * }
- */
-public class Solution {
- public boolean isBalanced(TreeNode root) {
- // Empty Tree is balanced
- if (root == null) {
- return true;
- }
- // Get max height of subtree child
- // Get max height of subtree child
- // compare height difference (cannot be more than 1)
- int leftHeight = 0;
- int rightHeight = 0;
- if (root.left != null) {
- leftHeight = getMaxHeight(root.left);
- }
- if (root.right != null) {
- rightHeight = getMaxHeight(root.right);
- }
- int heightDiff = Math.abs(leftHeight - rightHeight);
- // if passes height check
- // - Check if left subtree is balanced and if the right subtree is balanced
- // - If one of both are imbalanced, then the tree is imbalanced
- return heightDiff <= 1 && isBalanced(root.left) && isBalanced(root.right);
- }
-
- private int getMaxHeight(TreeNode root) {
- if (root == null) {
- return 0;
- }
- int leftHeight = 0;
- int rightHeight = 0;
- // Left
- if (root.left != null) {
- leftHeight = getMaxHeight(root.left);
- }
- // Right
- if (root.right != null) {
- rightHeight = getMaxHeight(root.right);
- }
- if (leftHeight > rightHeight) {
- return 1 + leftHeight;
- } else {
- return 1 + rightHeight;
- }
- }
-}
diff --git a/src.save/main/java/g0101_0200/s0111_minimum_depth_of_binary_tree/Solution.java b/src.save/main/java/g0101_0200/s0111_minimum_depth_of_binary_tree/Solution.java
deleted file mode 100644
index 9c47daf8d..000000000
--- a/src.save/main/java/g0101_0200/s0111_minimum_depth_of_binary_tree/Solution.java
+++ /dev/null
@@ -1,51 +0,0 @@
-package g0101_0200.s0111_minimum_depth_of_binary_tree;
-
-// #Easy #Depth_First_Search #Breadth_First_Search #Tree #Binary_Tree
-// #2022_02_22_Time_1_ms_(94.17%)_Space_89.5_MB_(59.57%)
-
-import com_github_leetcode.TreeNode;
-import java.util.LinkedList;
-import java.util.Queue;
-
-/*
- * Definition for a binary tree node.
- * public class TreeNode {
- * int val;
- * TreeNode left;
- * TreeNode right;
- * TreeNode() {}
- * TreeNode(int val) { this.val = val; }
- * TreeNode(int val, TreeNode left, TreeNode right) {
- * this.val = val;
- * this.left = left;
- * this.right = right;
- * }
- * }
- */
-public class Solution {
- public int minDepth(TreeNode root) {
- if (root == null) {
- return 0;
- }
- Queue queue = new LinkedList<>();
- queue.add(root);
- int d = 0;
- while (!queue.isEmpty()) {
- int size = queue.size();
- for (int i = 0; i < size; i++) {
- TreeNode current = queue.poll();
- if (current.left == null && current.right == null && d > 0) {
- return d + 1;
- }
- if (current.right != null) {
- queue.add(current.right);
- }
- if (current.left != null) {
- queue.add(current.left);
- }
- }
- d++;
- }
- return d;
- }
-}
diff --git a/src.save/main/java/g0101_0200/s0112_path_sum/Solution.java b/src.save/main/java/g0101_0200/s0112_path_sum/Solution.java
deleted file mode 100644
index dd88f4845..000000000
--- a/src.save/main/java/g0101_0200/s0112_path_sum/Solution.java
+++ /dev/null
@@ -1,33 +0,0 @@
-package g0101_0200.s0112_path_sum;
-
-// #Easy #Depth_First_Search #Tree #Binary_Tree #Data_Structure_I_Day_12_Tree
-// #2022_02_22_Time_0_ms_(100.00%)_Space_44_MB_(9.82%)
-
-import com_github_leetcode.TreeNode;
-
-/*
- * Definition for a binary tree node.
- * public class TreeNode {
- * int val;
- * TreeNode left;
- * TreeNode right;
- * TreeNode() {}
- * TreeNode(int val) { this.val = val; }
- * TreeNode(int val, TreeNode left, TreeNode right) {
- * this.val = val;
- * this.left = left;
- * this.right = right;
- * }
- * }
- */
-public class Solution {
- public boolean hasPathSum(TreeNode root, int sum) {
- if (root == null) {
- return false;
- }
- if (sum == root.val && root.left == null && root.right == null) {
- return true;
- }
- return hasPathSum(root.left, sum - root.val) || hasPathSum(root.right, sum - root.val);
- }
-}
diff --git a/src.save/main/java/g0101_0200/s0113_path_sum_ii/Solution.java b/src.save/main/java/g0101_0200/s0113_path_sum_ii/Solution.java
deleted file mode 100644
index d942b3ccd..000000000
--- a/src.save/main/java/g0101_0200/s0113_path_sum_ii/Solution.java
+++ /dev/null
@@ -1,49 +0,0 @@
-package g0101_0200.s0113_path_sum_ii;
-
-// #Medium #Depth_First_Search #Tree #Binary_Tree #Backtracking
-// #2022_02_22_Time_1_ms_(100.00%)_Space_42.4_MB_(47.38%)
-
-import com_github_leetcode.TreeNode;
-import java.util.ArrayList;
-import java.util.List;
-
-/*
- * Definition for a binary tree node.
- * public class TreeNode {
- * int val;
- * TreeNode left;
- * TreeNode right;
- * TreeNode() {}
- * TreeNode(int val) { this.val = val; }
- * TreeNode(int val, TreeNode left, TreeNode right) {
- * this.val = val;
- * this.left = left;
- * this.right = right;
- * }
- * }
- */
-public class Solution {
- public List> pathSum(TreeNode root, int targetSum) {
- List> res = new ArrayList<>();
- if (root == null) {
- return res;
- }
- recur(res, new ArrayList<>(), 0, targetSum, root);
- return res;
- }
-
- private void recur(
- List> res, ArrayList al, int sum, int targetSum, TreeNode root) {
- if (root == null) {
- return;
- }
- al.add(root.val);
- sum += root.val;
- if (sum == targetSum && root.left == null && root.right == null) {
- res.add(new ArrayList<>(al));
- }
- recur(res, al, sum, targetSum, root.left);
- recur(res, al, sum, targetSum, root.right);
- al.remove(al.size() - 1);
- }
-}
diff --git a/src.save/main/java/g0101_0200/s0114_flatten_binary_tree_to_linked_list/Solution.java b/src.save/main/java/g0101_0200/s0114_flatten_binary_tree_to_linked_list/Solution.java
deleted file mode 100644
index d7c4cf1b2..000000000
--- a/src.save/main/java/g0101_0200/s0114_flatten_binary_tree_to_linked_list/Solution.java
+++ /dev/null
@@ -1,51 +0,0 @@
-package g0101_0200.s0114_flatten_binary_tree_to_linked_list;
-
-// #Medium #Top_100_Liked_Questions #Depth_First_Search #Tree #Binary_Tree #Stack #Linked_List
-// #2022_02_22_Time_1_ms_(69.36%)_Space_42.6_MB_(22.05%)
-
-import com_github_leetcode.TreeNode;
-
-/*
- * Definition for a binary tree node.
- * public class TreeNode {
- * int val;
- * TreeNode left;
- * TreeNode right;
- * TreeNode() {}
- * TreeNode(int val) { this.val = val; }
- * TreeNode(int val, TreeNode left, TreeNode right) {
- * this.val = val;
- * this.left = left;
- * this.right = right;
- * }
- * }
- */
-public class Solution {
- public void flatten(TreeNode root) {
- if (root != null) {
- findTail(root);
- }
- }
-
- private TreeNode findTail(TreeNode root) {
- TreeNode left = root.left;
- TreeNode right = root.right;
- TreeNode tail;
- // find the tail of left subtree, tail means the most left leaf
- if (left != null) {
- tail = findTail(left);
- // stitch the right subtree below the tail
- root.left = null;
- root.right = left;
- tail.right = right;
- } else {
- tail = root;
- }
- // find tail of the right subtree
- if (tail.right == null) {
- return tail;
- } else {
- return findTail(tail.right);
- }
- }
-}
diff --git a/src.save/main/java/g0101_0200/s0114_flatten_binary_tree_to_linked_list/readme.md b/src.save/main/java/g0101_0200/s0114_flatten_binary_tree_to_linked_list/readme.md
deleted file mode 100644
index ea101ac1f..000000000
--- a/src.save/main/java/g0101_0200/s0114_flatten_binary_tree_to_linked_list/readme.md
+++ /dev/null
@@ -1,35 +0,0 @@
-114\. Flatten Binary Tree to Linked List
-
-Medium
-
-Given the `root` of a binary tree, flatten the tree into a "linked list":
-
-* The "linked list" should use the same `TreeNode` class where the `right` child pointer points to the next node in the list and the `left` child pointer is always `null`.
-* The "linked list" should be in the same order as a [**pre-order** **traversal**](https://en.wikipedia.org/wiki/Tree_traversal#Pre-order,_NLR) of the binary tree.
-
-**Example 1:**
-
-
-
-**Input:** root = [1,2,5,3,4,null,6]
-
-**Output:** [1,null,2,null,3,null,4,null,5,null,6]
-
-**Example 2:**
-
-**Input:** root = []
-
-**Output:** []
-
-**Example 3:**
-
-**Input:** root = [0]
-
-**Output:** [0]
-
-**Constraints:**
-
-* The number of nodes in the tree is in the range `[0, 2000]`.
-* `-100 <= Node.val <= 100`
-
-**Follow up:** Can you flatten the tree in-place (with `O(1)` extra space)?
\ No newline at end of file
diff --git a/src.save/main/java/g0101_0200/s0115_distinct_subsequences/Solution.java b/src.save/main/java/g0101_0200/s0115_distinct_subsequences/Solution.java
deleted file mode 100644
index 4d4f5b718..000000000
--- a/src.save/main/java/g0101_0200/s0115_distinct_subsequences/Solution.java
+++ /dev/null
@@ -1,46 +0,0 @@
-package g0101_0200.s0115_distinct_subsequences;
-
-// #Hard #String #Dynamic_Programming #2022_02_22_Time_3_ms_(99.53%)_Space_42.1_MB_(93.65%)
-
-public class Solution {
- public int numDistinct(String text, String text2) {
- if (text.length() < text2.length()) {
- return 0;
- }
- if (text.length() == text2.length()) {
- return (text.equals(text2) ? 1 : 0);
- }
- int move = text.length() - text2.length() + 2;
- // Only finite number of character in s can occupy first position in T. Same applies for
- // every character in T.
- int[] dp = new int[move];
- int j = 1;
- int k = 1;
- for (int i = 0; i < text2.length(); i++) {
- boolean firstMatch = true;
- for (; j < move; j++) {
- if (text2.charAt(i) == text.charAt(i + j - 1)) {
- if (firstMatch) {
- // Keep track of first match. To avoid useless comparisons on next
- // iteration.
- k = j;
- firstMatch = false;
- }
- if (i == 0) {
- dp[j] = 1;
- }
-
- dp[j] += dp[j - 1];
- } else {
- dp[j] = dp[j - 1];
- }
- }
- // No match found for current character of t in s. No point in checking others.
- if (dp[move - 1] == 0) {
- return 0;
- }
- j = k;
- }
- return dp[move - 1];
- }
-}
diff --git a/src.save/main/java/g0101_0200/s0116_populating_next_right_pointers_in_each_node/Solution.java b/src.save/main/java/g0101_0200/s0116_populating_next_right_pointers_in_each_node/Solution.java
deleted file mode 100644
index 680ac1a1e..000000000
--- a/src.save/main/java/g0101_0200/s0116_populating_next_right_pointers_in_each_node/Solution.java
+++ /dev/null
@@ -1,47 +0,0 @@
-package g0101_0200.s0116_populating_next_right_pointers_in_each_node;
-
-// #Medium #Top_Interview_Questions #Depth_First_Search #Breadth_First_Search #Tree #Binary_Tree
-// #Algorithm_I_Day_8_Breadth_First_Search_Depth_First_Search
-// #2022_02_22_Time_0_ms_(100.00%)_Space_47.4_MB_(15.15%)
-
-import com_github_leetcode.left_right.Node;
-
-/*
-// Definition for a Node.
-class Node {
- public int val;
- public Node left;
- public Node right;
- public Node next;
-
- public Node() {}
-
- public Node(int _val) {
- val = _val;
- }
-
- public Node(int _val, Node _left, Node _right, Node _next) {
- val = _val;
- left = _left;
- right = _right;
- next = _next;
- }
-};
-*/
-
-public class Solution {
- public Node connect(Node root) {
- if (root == null) {
- return null;
- }
- if (root.left != null && root.right != null) {
- root.left.next = root.right;
- }
- if (root.next != null && root.right != null) {
- root.right.next = root.next.left;
- }
- connect(root.left);
- connect(root.right);
- return root;
- }
-}
diff --git a/src.save/main/java/g0101_0200/s0117_populating_next_right_pointers_in_each_node_ii/Solution.java b/src.save/main/java/g0101_0200/s0117_populating_next_right_pointers_in_each_node_ii/Solution.java
deleted file mode 100644
index 92068903d..000000000
--- a/src.save/main/java/g0101_0200/s0117_populating_next_right_pointers_in_each_node_ii/Solution.java
+++ /dev/null
@@ -1,71 +0,0 @@
-package g0101_0200.s0117_populating_next_right_pointers_in_each_node_ii;
-
-// #Medium #Depth_First_Search #Breadth_First_Search #Tree #Binary_Tree
-// #2022_02_22_Time_0_ms_(100.00%)_Space_42.2_MB_(42.40%)
-
-import com_github_leetcode.left_right.Node;
-
-/*
-// Definition for a Node.
-class Node {
- public int val;
- public Node left;
- public Node right;
- public Node next;
-
- public Node() {}
-
- public Node(int _val) {
- val = _val;
- }
-
- public Node(int _val, Node _left, Node _right, Node _next) {
- val = _val;
- left = _left;
- right = _right;
- next = _next;
- }
-};
-*/
-
-public class Solution {
- public Node connect(Node root) {
- if (root == null) {
- return null;
- }
- if (root.left == null && root.right == null) {
- return root;
- }
-
- if (root.left != null) {
- if (root.right != null) {
- root.left.next = root.right;
- } else if (root.next != null) {
- root.left.next = adjacentRightNode(root.next);
- }
- }
- if (root.right != null) {
- root.right.next = adjacentRightNode(root.next);
- }
- connect(root.right);
- connect(root.left);
- return root;
- }
-
- private Node adjacentRightNode(Node root) {
- Node temp = root;
- while (temp != null) {
- if (temp.left == null && temp.right == null) {
- temp = temp.next;
- } else {
- if (temp.left != null) {
- return temp.left;
- }
- if (temp.right != null) {
- return temp.right;
- }
- }
- }
- return null;
- }
-}
diff --git a/src.save/main/java/g0101_0200/s0118_pascals_triangle/Solution.java b/src.save/main/java/g0101_0200/s0118_pascals_triangle/Solution.java
deleted file mode 100644
index 4a82e81cd..000000000
--- a/src.save/main/java/g0101_0200/s0118_pascals_triangle/Solution.java
+++ /dev/null
@@ -1,27 +0,0 @@
-package g0101_0200.s0118_pascals_triangle;
-
-// #Easy #Top_Interview_Questions #Array #Dynamic_Programming #Data_Structure_I_Day_4_Array
-// #Dynamic_Programming_I_Day_12 #2022_02_22_Time_1_ms_(62.34%)_Space_42_MB_(15.79%)
-
-import java.util.ArrayList;
-import java.util.List;
-
-@SuppressWarnings("java:S2589")
-public class Solution {
- public List> generate(int numRows) {
- List> output = new ArrayList<>();
- for (int i = 0; i < numRows; i++) {
- List currRow = new ArrayList<>();
- for (int j = 0; j <= i; j++) {
- if (j == 0 || j == i || i <= 1) {
- currRow.add(1);
- } else {
- int currCell = output.get(i - 1).get(j - 1) + output.get(i - 1).get(j);
- currRow.add(currCell);
- }
- }
- output.add(currRow);
- }
- return output;
- }
-}
diff --git a/src.save/main/java/g0101_0200/s0119_pascals_triangle_ii/Solution.java b/src.save/main/java/g0101_0200/s0119_pascals_triangle_ii/Solution.java
deleted file mode 100644
index 00a05c89f..000000000
--- a/src.save/main/java/g0101_0200/s0119_pascals_triangle_ii/Solution.java
+++ /dev/null
@@ -1,35 +0,0 @@
-package g0101_0200.s0119_pascals_triangle_ii;
-
-// #Easy #Array #Dynamic_Programming #Dynamic_Programming_I_Day_12
-// #2022_02_22_Time_0_ms_(100.00%)_Space_41.9_MB_(14.49%)
-
-import java.util.ArrayList;
-import java.util.List;
-
-public class Solution {
- public List getRow(int rowIndex) {
- int[] buffer = new int[rowIndex + 1];
- buffer[0] = 1;
- computeRow(buffer, 1);
- // Copy buffer to List of Integer.
- List ans = new ArrayList<>(buffer.length);
- for (int j : buffer) {
- ans.add(j);
- }
- return ans;
- }
-
- private void computeRow(int[] buffer, int k) {
- if (k >= buffer.length) {
- return;
- }
- int previous = buffer[0];
- for (int i = 1; i < k; i++) {
- int tmp = previous + buffer[i];
- previous = buffer[i];
- buffer[i] = tmp;
- }
- buffer[k] = 1;
- computeRow(buffer, k + 1);
- }
-}
diff --git a/src.save/main/java/g0101_0200/s0120_triangle/Solution.java b/src.save/main/java/g0101_0200/s0120_triangle/Solution.java
deleted file mode 100644
index 8107fac16..000000000
--- a/src.save/main/java/g0101_0200/s0120_triangle/Solution.java
+++ /dev/null
@@ -1,36 +0,0 @@
-package g0101_0200.s0120_triangle;
-
-// #Medium #Array #Dynamic_Programming #Algorithm_I_Day_12_Dynamic_Programming
-// #Dynamic_Programming_I_Day_13 #2022_02_22_Time_1_ms_(99.76%)_Space_41.7_MB_(43.52%)
-
-import java.util.Arrays;
-import java.util.List;
-
-public class Solution {
- public int minimumTotal(List> triangle) {
- if (triangle == null || triangle.isEmpty()) {
- return 0;
- }
- int[][] dp = new int[triangle.size()][triangle.get(triangle.size() - 1).size()];
- for (int[] temp : dp) {
- Arrays.fill(temp, -10001);
- }
- return dfs(triangle, dp, 0, 0);
- }
-
- private int dfs(List> triangle, int[][] dp, int row, int col) {
- if (row >= triangle.size()) {
- return 0;
- }
- if (dp[row][col] != -10001) {
- return dp[row][col];
- }
- int sum =
- triangle.get(row).get(col)
- + Math.min(
- dfs(triangle, dp, row + 1, col),
- dfs(triangle, dp, row + 1, col + 1));
- dp[row][col] = sum;
- return sum;
- }
-}
diff --git a/src.save/main/java/g0101_0200/s0121_best_time_to_buy_and_sell_stock/Solution.java b/src.save/main/java/g0101_0200/s0121_best_time_to_buy_and_sell_stock/Solution.java
deleted file mode 100644
index e5ce0ec23..000000000
--- a/src.save/main/java/g0101_0200/s0121_best_time_to_buy_and_sell_stock/Solution.java
+++ /dev/null
@@ -1,20 +0,0 @@
-package g0101_0200.s0121_best_time_to_buy_and_sell_stock;
-
-// #Easy #Top_100_Liked_Questions #Top_Interview_Questions #Array #Dynamic_Programming
-// #Data_Structure_I_Day_3_Array #Dynamic_Programming_I_Day_7
-// #2022_02_22_Time_2_ms_(85.25%)_Space_83.8_MB_(55.29%)
-
-public class Solution {
- public int maxProfit(int[] prices) {
- int maxProfit = 0;
- int min = prices[0];
- for (int i = 1; i < prices.length; i++) {
- if (prices[i] > min) {
- maxProfit = Math.max(maxProfit, prices[i] - min);
- } else {
- min = prices[i];
- }
- }
- return maxProfit;
- }
-}
diff --git a/src.save/main/java/g0101_0200/s0121_best_time_to_buy_and_sell_stock/readme.md b/src.save/main/java/g0101_0200/s0121_best_time_to_buy_and_sell_stock/readme.md
deleted file mode 100644
index 6e22ccf57..000000000
--- a/src.save/main/java/g0101_0200/s0121_best_time_to_buy_and_sell_stock/readme.md
+++ /dev/null
@@ -1,30 +0,0 @@
-121\. Best Time to Buy and Sell Stock
-
-Easy
-
-You are given an array `prices` where `prices[i]` is the price of a given stock on the `ith` day.
-
-You want to maximize your profit by choosing a **single day** to buy one stock and choosing a **different day in the future** to sell that stock.
-
-Return _the maximum profit you can achieve from this transaction_. If you cannot achieve any profit, return `0`.
-
-**Example 1:**
-
-**Input:** prices = [7,1,5,3,6,4]
-
-**Output:** 5
-
-**Explanation:** Buy on day 2 (price = 1) and sell on day 5 (price = 6), profit = 6-1 = 5. Note that buying on day 2 and selling on day 1 is not allowed because you must buy before you sell.
-
-**Example 2:**
-
-**Input:** prices = [7,6,4,3,1]
-
-**Output:** 0
-
-**Explanation:** In this case, no transactions are done and the max profit = 0.
-
-**Constraints:**
-
-* 1 <= prices.length <= 105
-* 0 <= prices[i] <= 104
\ No newline at end of file
diff --git a/src.save/main/java/g0101_0200/s0122_best_time_to_buy_and_sell_stock_ii/Solution.java b/src.save/main/java/g0101_0200/s0122_best_time_to_buy_and_sell_stock_ii/Solution.java
deleted file mode 100644
index e09ffc03a..000000000
--- a/src.save/main/java/g0101_0200/s0122_best_time_to_buy_and_sell_stock_ii/Solution.java
+++ /dev/null
@@ -1,16 +0,0 @@
-package g0101_0200.s0122_best_time_to_buy_and_sell_stock_ii;
-
-// #Medium #Top_Interview_Questions #Array #Dynamic_Programming #Greedy #Dynamic_Programming_I_Day_7
-// #2022_02_22_Time_2_ms_(34.31%)_Space_44.1_MB_(27.48%)
-
-public class Solution {
- public int maxProfit(int[] prices) {
- int max = 0;
- for (int i = 1; i < prices.length; i++) {
- if (prices[i] > prices[i - 1]) {
- max += prices[i] - prices[i - 1];
- }
- }
- return max;
- }
-}
diff --git a/src.save/main/java/g0101_0200/s0123_best_time_to_buy_and_sell_stock_iii/Solution.java b/src.save/main/java/g0101_0200/s0123_best_time_to_buy_and_sell_stock_iii/Solution.java
deleted file mode 100644
index de65d9f98..000000000
--- a/src.save/main/java/g0101_0200/s0123_best_time_to_buy_and_sell_stock_iii/Solution.java
+++ /dev/null
@@ -1,22 +0,0 @@
-package g0101_0200.s0123_best_time_to_buy_and_sell_stock_iii;
-
-// #Hard #Array #Dynamic_Programming #2022_02_22_Time_1_ms_(100.00%)_Space_58.7_MB_(75.57%)
-
-public class Solution {
- public int maxProfit(int[] prices) {
- if (prices.length == 0) {
- return 0;
- }
- int fb = Integer.MIN_VALUE;
- int sb = Integer.MIN_VALUE;
- int fs = 0;
- int ss = 0;
- for (int price : prices) {
- fb = Math.max(fb, -price);
- fs = Math.max(fs, fb + price);
- sb = Math.max(sb, fs - price);
- ss = Math.max(ss, sb + price);
- }
- return ss;
- }
-}
diff --git a/src.save/main/java/g0101_0200/s0124_binary_tree_maximum_path_sum/Solution.java b/src.save/main/java/g0101_0200/s0124_binary_tree_maximum_path_sum/Solution.java
deleted file mode 100644
index aeccd04ff..000000000
--- a/src.save/main/java/g0101_0200/s0124_binary_tree_maximum_path_sum/Solution.java
+++ /dev/null
@@ -1,44 +0,0 @@
-package g0101_0200.s0124_binary_tree_maximum_path_sum;
-
-// #Hard #Top_100_Liked_Questions #Top_Interview_Questions #Dynamic_Programming #Depth_First_Search
-// #Tree #Binary_Tree #2022_02_22_Time_1_ms_(76.01%)_Space_47.6_MB_(29.62%)
-
-import com_github_leetcode.TreeNode;
-
-/*
- * Definition for a binary tree node.
- * public class TreeNode {
- * int val;
- * TreeNode left;
- * TreeNode right;
- * TreeNode() {}
- * TreeNode(int val) { this.val = val; }
- * TreeNode(int val, TreeNode left, TreeNode right) {
- * this.val = val;
- * this.left = left;
- * this.right = right;
- * }
- * }
- */
-public class Solution {
- private int max = Integer.MIN_VALUE;
-
- private int helper(TreeNode root) {
- if (root == null) {
- return 0;
- }
- // to avoid the -ve values in left side we will compare them with 0
- int left = Math.max(0, helper(root.left));
- int right = Math.max(0, helper(root.right));
- int current = root.val + left + right;
- if (current > max) {
- max = current;
- }
- return root.val + Math.max(left, right);
- }
-
- public int maxPathSum(TreeNode root) {
- helper(root);
- return max;
- }
-}
diff --git a/src.save/main/java/g0101_0200/s0124_binary_tree_maximum_path_sum/readme.md b/src.save/main/java/g0101_0200/s0124_binary_tree_maximum_path_sum/readme.md
deleted file mode 100644
index 29f9180b2..000000000
--- a/src.save/main/java/g0101_0200/s0124_binary_tree_maximum_path_sum/readme.md
+++ /dev/null
@@ -1,34 +0,0 @@
-124\. Binary Tree Maximum Path Sum
-
-Hard
-
-A **path** in a binary tree is a sequence of nodes where each pair of adjacent nodes in the sequence has an edge connecting them. A node can only appear in the sequence **at most once**. Note that the path does not need to pass through the root.
-
-The **path sum** of a path is the sum of the node's values in the path.
-
-Given the `root` of a binary tree, return _the maximum **path sum** of any **non-empty** path_.
-
-**Example 1:**
-
-
-
-**Input:** root = [1,2,3]
-
-**Output:** 6
-
-**Explanation:** The optimal path is 2 -> 1 -> 3 with a path sum of 2 + 1 + 3 = 6.
-
-**Example 2:**
-
-
-
-**Input:** root = [-10,9,20,null,null,15,7]
-
-**Output:** 42
-
-**Explanation:** The optimal path is 15 -> 20 -> 7 with a path sum of 15 + 20 + 7 = 42.
-
-**Constraints:**
-
-* The number of nodes in the tree is in the range [1, 3 * 104].
-* `-1000 <= Node.val <= 1000`
\ No newline at end of file
diff --git a/src.save/main/java/g0101_0200/s0125_valid_palindrome/Solution.java b/src.save/main/java/g0101_0200/s0125_valid_palindrome/Solution.java
deleted file mode 100644
index 0ed8ed90c..000000000
--- a/src.save/main/java/g0101_0200/s0125_valid_palindrome/Solution.java
+++ /dev/null
@@ -1,59 +0,0 @@
-package g0101_0200.s0125_valid_palindrome;
-
-// #Easy #Top_Interview_Questions #String #Two_Pointers
-// #2022_02_22_Time_3_ms_(88.82%)_Space_43.4_MB_(41.11%)
-
-public class Solution {
- public boolean isPalindrome(String s) {
- int i = 0;
- int j = s.length() - 1;
- boolean res = true;
- while (res) {
- // Iterates through string to find first char which is alphanumeric.
- // Done to ignore non-alphanumeric characters.
- // Starts from 0 to j-1.
- while (i < j && isNotAlphaNumeric(s.charAt(i))) {
- i++;
- }
- // Similarly from j-1 to 0.
- while (i < j && isNotAlphaNumeric(s.charAt(j))) {
- j--;
- }
- // Checks if i is greater than or equal to j.
- // The main loop only needs to loop n / 2 times hence this condition (where n is string
- // length).
- if (i >= j) {
- break;
- }
- // Assigning found indices to variables.
- // The upperToLower function is used to convert characters, if upper case, to lower
- // case.
- // If already lower case, it'll return as it is.
- char left = upperToLower(s.charAt(i));
- char right = upperToLower(s.charAt(j));
- // If both variables are not same, result becomes false, and breaks out of the loop at
- // next iteration.
- if (left != right) {
- res = false;
- }
- i++;
- j--;
- }
- return res;
- }
-
- private boolean isNotAlphaNumeric(char c) {
- return (c < 'a' || c > 'z') && (c < 'A' || c > 'Z') && (c < '0' || c > '9');
- }
-
- private boolean isUpper(char c) {
- return c >= 'A' && c <= 'Z';
- }
-
- private char upperToLower(char c) {
- if (isUpper(c)) {
- c = (char) (c + 32);
- }
- return c;
- }
-}
diff --git a/src.save/main/java/g0101_0200/s0126_word_ladder_ii/Solution.java b/src.save/main/java/g0101_0200/s0126_word_ladder_ii/Solution.java
deleted file mode 100644
index dff44fc7c..000000000
--- a/src.save/main/java/g0101_0200/s0126_word_ladder_ii/Solution.java
+++ /dev/null
@@ -1,127 +0,0 @@
-package g0101_0200.s0126_word_ladder_ii;
-
-// #Hard #String #Hash_Table #Breadth_First_Search #Backtracking
-// #2022_02_22_Time_4_ms_(99.18%)_Space_42.4_MB_(70.92%)
-
-import java.util.ArrayList;
-import java.util.Arrays;
-import java.util.HashMap;
-import java.util.HashSet;
-import java.util.List;
-import java.util.Map;
-import java.util.Set;
-
-@SuppressWarnings("java:S135")
-public class Solution {
- public List> findLadders(String beginWord, String endWord, List wordList) {
- Map> graph = new HashMap<>();
- int targetLength = bfs(graph, beginWord, endWord, wordList);
- List> ans = new ArrayList<>();
- if (targetLength == 0) {
- return ans;
- }
- dfs(ans, new ArrayList<>(), targetLength, beginWord, endWord, graph);
- return ans;
- }
-
- private int bfs(
- Map> graph,
- String beginWord,
- String endWord,
- List wordList) {
- Set wordSet = new HashSet<>(wordList);
- if (!wordSet.contains(endWord)) {
- return 0;
- }
- wordSet.add(beginWord);
- // Bi BFS
- // two queue (startWord, endWord)
- Set set1 = new HashSet<>(Arrays.asList(beginWord));
- Set set2 = new HashSet<>(Arrays.asList(endWord));
- Set visited = new HashSet<>();
- boolean isReversed = false;
- // the number of words in the transformation sequence
- int length = 0;
- boolean found = false;
- while (!set1.isEmpty() && !found) {
- Set newSet = new HashSet<>();
- length++;
- // check next layer
- for (String word : set1) {
- visited.add(word);
- // check neighbor
- char[] arrWord = word.toCharArray();
- for (int i = 0; i < arrWord.length; i++) {
- char oldChar = arrWord[i];
- for (int j = 0; j < 26; j++) {
- char newChar = (char) ('a' + j);
- // skip original word
- if (newChar == oldChar) {
- continue;
- }
- arrWord[i] = newChar;
- String newWord = String.valueOf(arrWord);
- if (!wordSet.contains(newWord)) {
- continue;
- }
- if (set2.contains(newWord)) {
- found = true;
- }
- if (visited.contains(newWord)) {
- continue;
- }
- newSet.add(newWord);
- if (!isReversed) {
- graph.putIfAbsent(word, new HashSet<>());
- graph.get(word).add(newWord);
- } else {
- graph.putIfAbsent(newWord, new HashSet<>());
- graph.get(newWord).add(word);
- }
- }
- // revert change
- arrWord[i] = oldChar;
- }
- }
- set1 = newSet;
- // swap queue
- // always make sure set1 is the smaller set
- // so we can end early if there is no path from begin to end word (set1 will be empty)
- if (set1.size() > set2.size()) {
- Set tmpVisited = set1;
- set1 = set2;
- set2 = tmpVisited;
- isReversed = !isReversed;
- }
- }
- if (!found) {
- return 0;
- }
- return length + 1;
- }
-
- private void dfs(
- List> ans,
- List path,
- int targetLength,
- String beginWord,
- String endWord,
- Map> graph) {
- path.add(beginWord);
- if (path.size() > targetLength) {
- path.remove(path.size() - 1);
- return;
- }
- if (beginWord.equals(endWord)) {
- ans.add(new ArrayList<>(path));
- path.remove(path.size() - 1);
- return;
- }
- if (graph.containsKey(beginWord)) {
- for (String neighbor : graph.get(beginWord)) {
- dfs(ans, path, targetLength, neighbor, endWord, graph);
- }
- }
- path.remove(path.size() - 1);
- }
-}
diff --git a/src.save/main/java/g0101_0200/s0127_word_ladder/Solution.java b/src.save/main/java/g0101_0200/s0127_word_ladder/Solution.java
deleted file mode 100644
index 8e6fa9973..000000000
--- a/src.save/main/java/g0101_0200/s0127_word_ladder/Solution.java
+++ /dev/null
@@ -1,53 +0,0 @@
-package g0101_0200.s0127_word_ladder;
-
-// #Hard #Top_Interview_Questions #String #Hash_Table #Breadth_First_Search
-// #2022_02_22_Time_32_ms_(94.39%)_Space_53.6_MB_(60.33%)
-
-import java.util.HashSet;
-import java.util.List;
-import java.util.Set;
-
-public class Solution {
- public int ladderLength(String beginWord, String endWord, List wordDict) {
- Set beginSet = new HashSet<>();
- Set endSet = new HashSet<>();
- Set wordSet = new HashSet<>(wordDict);
- Set visited = new HashSet<>();
- if (!wordDict.contains(endWord)) {
- return 0;
- }
- int len = 1;
- int strLen = beginWord.length();
- beginSet.add(beginWord);
- endSet.add(endWord);
- while (!beginSet.isEmpty() && !endSet.isEmpty()) {
- if (beginSet.size() > endSet.size()) {
- Set temp = beginSet;
- beginSet = endSet;
- endSet = temp;
- }
- Set tempSet = new HashSet<>();
- for (String s : beginSet) {
- char[] chars = s.toCharArray();
- for (int i = 0; i < strLen; i++) {
- char old = chars[i];
- for (char j = 'a'; j <= 'z'; j++) {
- chars[i] = j;
- String temp = new String(chars);
- if (endSet.contains(temp)) {
- return len + 1;
- }
- if (!visited.contains(temp) && wordSet.contains(temp)) {
- tempSet.add(temp);
- visited.add(temp);
- }
- }
- chars[i] = old;
- }
- }
- beginSet = tempSet;
- len++;
- }
- return 0;
- }
-}
diff --git a/src.save/main/java/g0101_0200/s0128_longest_consecutive_sequence/Solution.java b/src.save/main/java/g0101_0200/s0128_longest_consecutive_sequence/Solution.java
deleted file mode 100644
index f44d19023..000000000
--- a/src.save/main/java/g0101_0200/s0128_longest_consecutive_sequence/Solution.java
+++ /dev/null
@@ -1,31 +0,0 @@
-package g0101_0200.s0128_longest_consecutive_sequence;
-
-// #Medium #Top_100_Liked_Questions #Top_Interview_Questions #Array #Hash_Table #Union_Find
-// #2022_02_22_Time_17_ms_(84.46%)_Space_61.3_MB_(42.78%)
-
-import java.util.Arrays;
-
-@SuppressWarnings("java:S135")
-public class Solution {
- public int longestConsecutive(int[] nums) {
- if (nums.length == 0) {
- return 0;
- }
- Arrays.sort(nums);
- int max = Integer.MIN_VALUE;
- int thsMax = 1;
- for (int i = 0; i < nums.length - 1; i++) {
- if (nums[i + 1] == nums[i] + 1) {
- thsMax += 1;
- continue;
- }
- if (nums[i + 1] == nums[i]) {
- continue;
- }
- // Start of a new Sequene
- max = Math.max(max, thsMax);
- thsMax = 1;
- }
- return Math.max(max, thsMax);
- }
-}
diff --git a/src.save/main/java/g0101_0200/s0128_longest_consecutive_sequence/readme.md b/src.save/main/java/g0101_0200/s0128_longest_consecutive_sequence/readme.md
deleted file mode 100644
index b5169398a..000000000
--- a/src.save/main/java/g0101_0200/s0128_longest_consecutive_sequence/readme.md
+++ /dev/null
@@ -1,26 +0,0 @@
-128\. Longest Consecutive Sequence
-
-Medium
-
-Given an unsorted array of integers `nums`, return _the length of the longest consecutive elements sequence._
-
-You must write an algorithm that runs in `O(n)` time.
-
-**Example 1:**
-
-**Input:** nums = [100,4,200,1,3,2]
-
-**Output:** 4
-
-**Explanation:** The longest consecutive elements sequence is `[1, 2, 3, 4]`. Therefore its length is 4.
-
-**Example 2:**
-
-**Input:** nums = [0,3,7,2,5,8,4,6,0,1]
-
-**Output:** 9
-
-**Constraints:**
-
-* 0 <= nums.length <= 105
-* -109 <= nums[i] <= 109
\ No newline at end of file
diff --git a/src.save/main/java/g0101_0200/s0129_sum_root_to_leaf_numbers/Solution.java b/src.save/main/java/g0101_0200/s0129_sum_root_to_leaf_numbers/Solution.java
deleted file mode 100644
index f7fcd3cd0..000000000
--- a/src.save/main/java/g0101_0200/s0129_sum_root_to_leaf_numbers/Solution.java
+++ /dev/null
@@ -1,43 +0,0 @@
-package g0101_0200.s0129_sum_root_to_leaf_numbers;
-
-// #Medium #Depth_First_Search #Tree #Binary_Tree
-// #2022_02_22_Time_0_ms_(100.00%)_Space_39.9_MB_(36.66%)
-
-import com_github_leetcode.TreeNode;
-
-/*
- * Definition for a binary tree node.
- * public class TreeNode {
- * int val;
- * TreeNode left;
- * TreeNode right;
- * TreeNode() {}
- * TreeNode(int val) { this.val = val; }
- * TreeNode(int val, TreeNode left, TreeNode right) {
- * this.val = val;
- * this.left = left;
- * this.right = right;
- * }
- * }
- */
-public class Solution {
- private int sum = 0;
-
- public int sumNumbers(TreeNode root) {
- recurseSum(root, 0);
- return sum;
- }
-
- private void recurseSum(TreeNode node, int curNum) {
- if (node.left == null && node.right == null) {
- sum += 10 * curNum + node.val;
- } else {
- if (node.left != null) {
- recurseSum(node.left, 10 * curNum + node.val);
- }
- if (node.right != null) {
- recurseSum(node.right, 10 * curNum + node.val);
- }
- }
- }
-}
diff --git a/src.save/main/java/g0101_0200/s0130_surrounded_regions/Solution.java b/src.save/main/java/g0101_0200/s0130_surrounded_regions/Solution.java
deleted file mode 100644
index dcf39188a..000000000
--- a/src.save/main/java/g0101_0200/s0130_surrounded_regions/Solution.java
+++ /dev/null
@@ -1,67 +0,0 @@
-package g0101_0200.s0130_surrounded_regions;
-
-// #Medium #Top_Interview_Questions #Array #Depth_First_Search #Breadth_First_Search #Matrix
-// #Union_Find #2022_02_22_Time_2_ms_(80.58%)_Space_52_MB_(17.02%)
-
-public class Solution {
- public void solve(char[][] board) {
- // Edge case, empty grid
- if (board.length == 0) {
- return;
- }
- // Traverse first and last rows ( boundaries)
- for (int i = 0; i < board[0].length; i++) {
- // first row
- if (board[0][i] == 'O') {
- // It will covert O and all it's touching O's to #
- dfs(board, 0, i);
- }
- // last row
- if (board[board.length - 1][i] == 'O') {
- // Coverts O's to #'s (same thing as above)
- dfs(board, board.length - 1, i);
- }
- }
- // Traverse first and last Column (boundaries)
- for (int i = 0; i < board.length; i++) {
- // first Column
- if (board[i][0] == 'O') {
- // Converts O's to #'s
- dfs(board, i, 0);
- }
- // last Column
- if (board[i][board[0].length - 1] == 'O') {
- // Coverts O's to #'s
- dfs(board, i, board[0].length - 1);
- }
- }
- // Traverse through entire matrix
- for (int i = 0; i < board.length; i++) {
- for (int j = 0; j < board[0].length; j++) {
- if (board[i][j] == 'O') {
- // Convert O's to X's
- board[i][j] = 'X';
- }
- if (board[i][j] == '#') {
- // Convert #'s to O's
- board[i][j] = 'O';
- }
- }
- }
- }
-
- void dfs(char[][] board, int row, int column) {
- if (row < 0
- || row >= board.length
- || column < 0
- || column >= board[0].length
- || board[row][column] != 'O') {
- return;
- }
- board[row][column] = '#';
- dfs(board, row + 1, column);
- dfs(board, row - 1, column);
- dfs(board, row, column + 1);
- dfs(board, row, column - 1);
- }
-}
diff --git a/src.save/main/java/g0101_0200/s0131_palindrome_partitioning/Solution.java b/src.save/main/java/g0101_0200/s0131_palindrome_partitioning/Solution.java
deleted file mode 100644
index c7ec3e5ef..000000000
--- a/src.save/main/java/g0101_0200/s0131_palindrome_partitioning/Solution.java
+++ /dev/null
@@ -1,38 +0,0 @@
-package g0101_0200.s0131_palindrome_partitioning;
-
-// #Medium #Top_100_Liked_Questions #Top_Interview_Questions #String #Dynamic_Programming
-// #Backtracking #2022_02_22_Time_19_ms_(53.74%)_Space_194.8_MB_(9.14%)
-
-import java.util.ArrayList;
-import java.util.List;
-
-@SuppressWarnings("java:S5413")
-public class Solution {
- public List> partition(String s) {
- List> res = new ArrayList<>();
- backtracking(res, new ArrayList<>(), s, 0);
- return res;
- }
-
- private void backtracking(List> res, List currArr, String s, int start) {
- if (start == s.length()) {
- res.add(new ArrayList<>(currArr));
- }
- for (int end = start; end < s.length(); end++) {
- if (!isPanlindrome(s, start, end)) {
- continue;
- }
- currArr.add(s.substring(start, end + 1));
- backtracking(res, currArr, s, end + 1);
- currArr.remove(currArr.size() - 1);
- }
- }
-
- private boolean isPanlindrome(String s, int start, int end) {
- while (start < end && s.charAt(start) == s.charAt(end)) {
- start++;
- end--;
- }
- return start >= end;
- }
-}
diff --git a/src.save/main/java/g0101_0200/s0131_palindrome_partitioning/readme.md b/src.save/main/java/g0101_0200/s0131_palindrome_partitioning/readme.md
deleted file mode 100644
index 450d8798f..000000000
--- a/src.save/main/java/g0101_0200/s0131_palindrome_partitioning/readme.md
+++ /dev/null
@@ -1,24 +0,0 @@
-131\. Palindrome Partitioning
-
-Medium
-
-Given a string `s`, partition `s` such that every substring of the partition is a **palindrome**. Return all possible palindrome partitioning of `s`.
-
-A **palindrome** string is a string that reads the same backward as forward.
-
-**Example 1:**
-
-**Input:** s = "aab"
-
-**Output:** [["a","a","b"],["aa","b"]]
-
-**Example 2:**
-
-**Input:** s = "a"
-
-**Output:** [["a"]]
-
-**Constraints:**
-
-* `1 <= s.length <= 16`
-* `s` contains only lowercase English letters.
\ No newline at end of file
diff --git a/src.save/main/java/g0101_0200/s0132_palindrome_partitioning_ii/Solution.java b/src.save/main/java/g0101_0200/s0132_palindrome_partitioning_ii/Solution.java
deleted file mode 100644
index 905ab56eb..000000000
--- a/src.save/main/java/g0101_0200/s0132_palindrome_partitioning_ii/Solution.java
+++ /dev/null
@@ -1,30 +0,0 @@
-package g0101_0200.s0132_palindrome_partitioning_ii;
-
-// #Hard #String #Dynamic_Programming #2022_02_22_Time_2_ms_(99.72%)_Space_41.7_MB_(75.39%)
-
-import java.util.Arrays;
-
-public class Solution {
- public int minCut(String s) {
- int n = s.length();
- char[] t = s.toCharArray();
- int[] dp = new int[n + 1];
- Arrays.fill(dp, Integer.MAX_VALUE);
- dp[0] = -1;
- int i = 0;
- while (i < n) {
- expandAround(t, i, i, dp);
- expandAround(t, i, i + 1, dp);
- i++;
- }
- return dp[n];
- }
-
- private void expandAround(char[] t, int i, int j, int[] dp) {
- while (i >= 0 && j < t.length && t[i] == t[j]) {
- dp[j + 1] = Math.min(dp[j + 1], dp[i] + 1);
- i--;
- j++;
- }
- }
-}
diff --git a/src.save/main/java/g0101_0200/s0133_clone_graph/Solution.java b/src.save/main/java/g0101_0200/s0133_clone_graph/Solution.java
deleted file mode 100644
index 7d9d03169..000000000
--- a/src.save/main/java/g0101_0200/s0133_clone_graph/Solution.java
+++ /dev/null
@@ -1,34 +0,0 @@
-package g0101_0200.s0133_clone_graph;
-
-// #Medium #Hash_Table #Depth_First_Search #Breadth_First_Search #Graph
-// #2022_02_22_Time_55_ms_(16.92%)_Space_43.2_MB_(24.32%)
-
-import com_github_leetcode.Node;
-import java.util.ArrayList;
-import java.util.HashMap;
-import java.util.Map;
-
-public class Solution {
- public Node cloneGraph(Node node) {
- return cloneGraph(node, new HashMap<>());
- }
-
- private Node cloneGraph(Node node, Map processedNodes) {
- if (node == null) {
- return null;
- } else if (processedNodes.get(node) != null) {
- return processedNodes.get(node);
- }
- Node newNode = new Node();
- processedNodes.put(node, newNode);
- newNode.val = node.val;
- newNode.neighbors = new ArrayList<>();
- for (Node neighbor : node.neighbors) {
- Node clonedNeighbor = cloneGraph(neighbor, processedNodes);
- if (clonedNeighbor != null) {
- newNode.neighbors.add(clonedNeighbor);
- }
- }
- return newNode;
- }
-}
diff --git a/src.save/main/java/g0101_0200/s0134_gas_station/Solution.java b/src.save/main/java/g0101_0200/s0134_gas_station/Solution.java
deleted file mode 100644
index 7a3b67e23..000000000
--- a/src.save/main/java/g0101_0200/s0134_gas_station/Solution.java
+++ /dev/null
@@ -1,30 +0,0 @@
-package g0101_0200.s0134_gas_station;
-
-// #Medium #Top_Interview_Questions #Array #Greedy
-// #2022_02_22_Time_3_ms_(61.54%)_Space_81.3_MB_(7.19%)
-
-public class Solution {
- public int canCompleteCircuit(int[] gas, int[] cost) {
- int sumGas = 0;
- int sumCost = 0;
- int curGas = 0;
- int result = -1;
- for (int i = 0; i < gas.length; i++) {
- curGas += gas[i] - cost[i];
- // re-calculate the starting point
- if (curGas < 0) {
- result = -1;
- curGas = 0;
- } else if (result == -1) {
- // set initial starting point
- result = i;
- }
- sumGas += gas[i];
- sumCost += cost[i];
- }
- if (sumGas < sumCost) {
- return -1;
- }
- return result;
- }
-}
diff --git a/src.save/main/java/g0101_0200/s0135_candy/Solution.java b/src.save/main/java/g0101_0200/s0135_candy/Solution.java
deleted file mode 100644
index 9cf2254ec..000000000
--- a/src.save/main/java/g0101_0200/s0135_candy/Solution.java
+++ /dev/null
@@ -1,27 +0,0 @@
-package g0101_0200.s0135_candy;
-
-// #Hard #Array #Greedy #2022_02_22_Time_3_ms_(76.49%)_Space_51.4_MB_(28.53%)
-
-import java.util.Arrays;
-
-public class Solution {
- public int candy(int[] ratings) {
- int[] candies = new int[ratings.length];
- Arrays.fill(candies, 1);
- for (int i = 0; i < ratings.length - 1; i++) {
- if (ratings[i + 1] > ratings[i]) {
- candies[i + 1] = candies[i] + 1;
- }
- }
- for (int i = ratings.length - 1; i > 0; i--) {
- if (ratings[i - 1] > ratings[i] && candies[i - 1] < candies[i] + 1) {
- candies[i - 1] = candies[i] + 1;
- }
- }
- int total = 0;
- for (int candy : candies) {
- total += candy;
- }
- return total;
- }
-}
diff --git a/src.save/main/java/g0101_0200/s0136_single_number/Solution.java b/src.save/main/java/g0101_0200/s0136_single_number/Solution.java
deleted file mode 100644
index c3823e8e1..000000000
--- a/src.save/main/java/g0101_0200/s0136_single_number/Solution.java
+++ /dev/null
@@ -1,14 +0,0 @@
-package g0101_0200.s0136_single_number;
-
-// #Easy #Top_100_Liked_Questions #Top_Interview_Questions #Array #Bit_Manipulation
-// #Algorithm_I_Day_14_Bit_Manipulation #2022_02_22_Time_2_ms_(58.97%)_Space_50.1_MB_(53.89%)
-
-public class Solution {
- public int singleNumber(int[] nums) {
- int res = 0;
- for (int num : nums) {
- res ^= num;
- }
- return res;
- }
-}
diff --git a/src.save/main/java/g0101_0200/s0136_single_number/readme.md b/src.save/main/java/g0101_0200/s0136_single_number/readme.md
deleted file mode 100644
index 5f9d3dfca..000000000
--- a/src.save/main/java/g0101_0200/s0136_single_number/readme.md
+++ /dev/null
@@ -1,31 +0,0 @@
-136\. Single Number
-
-Easy
-
-Given a **non-empty** array of integers `nums`, every element appears _twice_ except for one. Find that single one.
-
-You must implement a solution with a linear runtime complexity and use only constant extra space.
-
-**Example 1:**
-
-**Input:** nums = [2,2,1]
-
-**Output:** 1
-
-**Example 2:**
-
-**Input:** nums = [4,1,2,1,2]
-
-**Output:** 4
-
-**Example 3:**
-
-**Input:** nums = [1]
-
-**Output:** 1
-
-**Constraints:**
-
-* 1 <= nums.length <= 3 * 104
-* -3 * 104 <= nums[i] <= 3 * 104
-* Each element in the array appears twice except for one element which appears only once.
\ No newline at end of file
diff --git a/src.save/main/java/g0101_0200/s0137_single_number_ii/Solution.java b/src.save/main/java/g0101_0200/s0137_single_number_ii/Solution.java
deleted file mode 100644
index 219f63163..000000000
--- a/src.save/main/java/g0101_0200/s0137_single_number_ii/Solution.java
+++ /dev/null
@@ -1,15 +0,0 @@
-package g0101_0200.s0137_single_number_ii;
-
-// #Medium #Array #Bit_Manipulation #2022_02_22_Time_1_ms_(91.46%)_Space_43.6_MB_(37.14%)
-
-public class Solution {
- public int singleNumber(int[] nums) {
- int ones = 0;
- int twos = 0;
- for (int num : nums) {
- ones = (ones ^ num) & (~twos);
- twos = (twos ^ num) & (~ones);
- }
- return ones;
- }
-}
diff --git a/src.save/main/java/g0101_0200/s0138_copy_list_with_random_pointer/Solution.java b/src.save/main/java/g0101_0200/s0138_copy_list_with_random_pointer/Solution.java
deleted file mode 100644
index 15ecd7ba6..000000000
--- a/src.save/main/java/g0101_0200/s0138_copy_list_with_random_pointer/Solution.java
+++ /dev/null
@@ -1,70 +0,0 @@
-package g0101_0200.s0138_copy_list_with_random_pointer;
-
-// #Medium #Top_100_Liked_Questions #Top_Interview_Questions #Hash_Table #Linked_List
-// #2022_02_22_Time_0_ms_(100.00%)_Space_41.7_MB_(78.31%)
-
-import com_github_leetcode.random.Node;
-
-/*
-// Definition for a Node.
-class Node {
- public int val;
- public Node next;
- public Node random;
-
- public Node() {}
-
- public Node(int _val,Node _next,Node _random) {
- val = _val;
- next = _next;
- random = _random;
- }
-};
-*/
-public class Solution {
- public Node copyRandomList(Node head) {
- if (head == null) {
- return null;
- }
- // first pass to have a clone node point to the next node. ie A->B becomes A->clonedNode->B
- Node curr = head;
- while (curr != null) {
- Node clonedNode = new Node(curr.val);
- clonedNode.next = curr.next;
- curr.next = clonedNode;
- curr = clonedNode.next;
- }
- curr = head;
- // second pass to make the cloned node's random pointer point to the orginal node's randome
- // pointer.
- // ie. A's random pointer becomes ClonedNode's random pointer
- while (curr != null) {
- if (curr.random != null) {
- curr.next.random = curr.random.next;
- } else {
- curr.next.random = null;
- }
- curr = curr.next.next;
- }
- curr = head;
- // third pass to restore the links and return the head of the cloned nodes' list.
- Node newHead = null;
- while (curr != null) {
- Node clonedNode;
- if (newHead == null) {
- clonedNode = curr.next;
- newHead = clonedNode;
- } else {
- clonedNode = curr.next;
- }
- curr.next = clonedNode.next;
- if (curr.next != null) {
- clonedNode.next = curr.next.next;
- } else {
- clonedNode.next = null;
- }
- curr = curr.next;
- }
- return newHead;
- }
-}
diff --git a/src.save/main/java/g0101_0200/s0138_copy_list_with_random_pointer/readme.md b/src.save/main/java/g0101_0200/s0138_copy_list_with_random_pointer/readme.md
deleted file mode 100644
index 9e2f93921..000000000
--- a/src.save/main/java/g0101_0200/s0138_copy_list_with_random_pointer/readme.md
+++ /dev/null
@@ -1,56 +0,0 @@
-138\. Copy List with Random Pointer
-
-Medium
-
-A linked list of length `n` is given such that each node contains an additional random pointer, which could point to any node in the list, or `null`.
-
-Construct a [**deep copy**](https://en.wikipedia.org/wiki/Object_copying#Deep_copy) of the list. The deep copy should consist of exactly `n` **brand new** nodes, where each new node has its value set to the value of its corresponding original node. Both the `next` and `random` pointer of the new nodes should point to new nodes in the copied list such that the pointers in the original list and copied list represent the same list state. **None of the pointers in the new list should point to nodes in the original list**.
-
-For example, if there are two nodes `X` and `Y` in the original list, where `X.random --> Y`, then for the corresponding two nodes `x` and `y` in the copied list, `x.random --> y`.
-
-Return _the head of the copied linked list_.
-
-The linked list is represented in the input/output as a list of `n` nodes. Each node is represented as a pair of `[val, random_index]` where:
-
-* `val`: an integer representing `Node.val`
-* `random_index`: the index of the node (range from `0` to `n-1`) that the `random` pointer points to, or `null` if it does not point to any node.
-
-Your code will **only** be given the `head` of the original linked list.
-
-**Example 1:**
-
-
-
-**Input:** head = [[7,null],[13,0],[11,4],[10,2],[1,0]]
-
-**Output:** [[7,null],[13,0],[11,4],[10,2],[1,0]]
-
-**Example 2:**
-
-
-
-**Input:** head = [[1,1],[2,1]]
-
-**Output:** [[1,1],[2,1]]
-
-**Example 3:**
-
-****
-
-**Input:** head = [[3,null],[3,0],[3,null]]
-
-**Output:** [[3,null],[3,0],[3,null]]
-
-**Example 4:**
-
-**Input:** head = []
-
-**Output:** []
-
-**Explanation:** The given linked list is empty (null pointer), so return null.
-
-**Constraints:**
-
-* `0 <= n <= 1000`
-* `-10000 <= Node.val <= 10000`
-* `Node.random` is `null` or is pointing to some node in the linked list.
\ No newline at end of file
diff --git a/src.save/main/java/g0101_0200/s0139_word_break/Solution.java b/src.save/main/java/g0101_0200/s0139_word_break/Solution.java
deleted file mode 100644
index 48dc53970..000000000
--- a/src.save/main/java/g0101_0200/s0139_word_break/Solution.java
+++ /dev/null
@@ -1,44 +0,0 @@
-package g0101_0200.s0139_word_break;
-
-// #Medium #Top_100_Liked_Questions #Top_Interview_Questions #String #Hash_Table
-// #Dynamic_Programming #Trie #Memoization #Dynamic_Programming_I_Day_9
-// #2022_02_22_Time_2_ms_(96.55%)_Space_42.2_MB_(63.03%)
-
-import java.util.HashSet;
-import java.util.List;
-import java.util.Set;
-
-public class Solution {
- public boolean wordBreak(String s, List wordDict) {
- Set set = new HashSet<>();
- int max = 0;
- boolean[] flag = new boolean[s.length() + 1];
- for (String st : wordDict) {
- set.add(st);
- if (max < st.length()) {
- max = st.length();
- }
- }
- for (int i = 1; i <= max; i++) {
- if (dfs(s, 0, i, max, set, flag)) {
- return true;
- }
- }
- return false;
- }
-
- private boolean dfs(String s, int start, int end, int max, Set set, boolean[] flag) {
- if (!flag[end] && set.contains(s.substring(start, end))) {
- flag[end] = true;
- if (end == s.length()) {
- return true;
- }
- for (int i = 1; i <= max; i++) {
- if (end + i <= s.length() && dfs(s, end, end + i, max, set, flag)) {
- return true;
- }
- }
- }
- return false;
- }
-}
diff --git a/src.save/main/java/g0101_0200/s0140_word_break_ii/Solution.java b/src.save/main/java/g0101_0200/s0140_word_break_ii/Solution.java
deleted file mode 100644
index d28cfc567..000000000
--- a/src.save/main/java/g0101_0200/s0140_word_break_ii/Solution.java
+++ /dev/null
@@ -1,38 +0,0 @@
-package g0101_0200.s0140_word_break_ii;
-
-// #Hard #Top_Interview_Questions #String #Hash_Table #Dynamic_Programming #Backtracking #Trie
-// #Memoization #2022_02_22_Time_1_ms_(95.98%)_Space_42.9_MB_(6.23%)
-
-import java.util.HashSet;
-import java.util.LinkedList;
-import java.util.List;
-import java.util.Set;
-
-public class Solution {
- public List wordBreak(String s, List wordDict) {
- List result = new LinkedList<>();
- Set wordSet = new HashSet<>(wordDict);
- dfs(s, wordSet, 0, new StringBuilder(), result);
- return result;
- }
-
- private void dfs(
- String s, Set wordSet, int index, StringBuilder sb, List result) {
- if (index == s.length()) {
- if (sb.charAt(sb.length() - 1) == ' ') {
- sb.setLength(sb.length() - 1);
- }
- result.add(sb.toString());
- return;
- }
- int len = sb.length();
- for (int i = index + 1; i <= s.length(); ++i) {
- String subs = s.substring(index, i);
- if (wordSet.contains(subs)) {
- sb.append(subs).append(" ");
- dfs(s, wordSet, i, sb, result);
- }
- sb.setLength(len);
- }
- }
-}
diff --git a/src.save/main/java/g0101_0200/s0141_linked_list_cycle/Solution.java b/src.save/main/java/g0101_0200/s0141_linked_list_cycle/Solution.java
deleted file mode 100644
index c14cb2b8c..000000000
--- a/src.save/main/java/g0101_0200/s0141_linked_list_cycle/Solution.java
+++ /dev/null
@@ -1,35 +0,0 @@
-package g0101_0200.s0141_linked_list_cycle;
-
-// #Easy #Top_100_Liked_Questions #Top_Interview_Questions #Hash_Table #Two_Pointers #Linked_List
-// #Data_Structure_I_Day_7_Linked_List #2022_02_23_Time_0_ms_(100.00%)_Space_46.5_MB_(9.38%)
-
-import com_github_leetcode.ListNode;
-
-/*
- * Definition for singly-linked list.
- * class ListNode {
- * int val;
- * ListNode next;
- * ListNode(int x) {
- * val = x;
- * next = null;
- * }
- * }
- */
-public class Solution {
- public boolean hasCycle(ListNode head) {
- if (head == null) {
- return false;
- }
- ListNode fast = head.next;
- ListNode slow = head;
- while (fast != null && fast.next != null) {
- if (fast == slow) {
- return true;
- }
- fast = fast.next.next;
- slow = slow.next;
- }
- return false;
- }
-}
diff --git a/src.save/main/java/g0101_0200/s0142_linked_list_cycle_ii/Solution.java b/src.save/main/java/g0101_0200/s0142_linked_list_cycle_ii/Solution.java
deleted file mode 100644
index fec4a43e8..000000000
--- a/src.save/main/java/g0101_0200/s0142_linked_list_cycle_ii/Solution.java
+++ /dev/null
@@ -1,44 +0,0 @@
-package g0101_0200.s0142_linked_list_cycle_ii;
-
-// #Medium #Top_100_Liked_Questions #Hash_Table #Two_Pointers #Linked_List
-// #Data_Structure_II_Day_10_Linked_List #2022_02_23_Time_0_ms_(100.00%)_Space_45_MB_(12.41%)
-
-import com_github_leetcode.ListNode;
-
-/*
- * Definition for singly-linked list.
- * class ListNode {
- * int val;
- * ListNode next;
- * ListNode(int x) {
- * val = x;
- * next = null;
- * }
- * }
- */
-public class Solution {
- public ListNode detectCycle(ListNode head) {
- if (head == null || head.next == null) {
- return null;
- }
- ListNode slow = head;
- ListNode fast = head;
- while (fast != null && fast.next != null) {
- fast = fast.next.next;
- slow = slow.next;
- // intersected inside the loop.
- if (slow == fast) {
- break;
- }
- }
- if (fast == null || fast.next == null) {
- return null;
- }
- slow = head;
- while (slow != fast) {
- slow = slow.next;
- fast = fast.next;
- }
- return slow;
- }
-}
diff --git a/src.save/main/java/g0101_0200/s0143_reorder_list/Solution.java b/src.save/main/java/g0101_0200/s0143_reorder_list/Solution.java
deleted file mode 100644
index c35b2e155..000000000
--- a/src.save/main/java/g0101_0200/s0143_reorder_list/Solution.java
+++ /dev/null
@@ -1,48 +0,0 @@
-package g0101_0200.s0143_reorder_list;
-
-// #Medium #Two_Pointers #Stack #Linked_List #Recursion #Data_Structure_II_Day_13_Linked_List
-// #2022_02_23_Time_2_ms_(72.16%)_Space_55.3_MB_(5.51%)
-
-import com_github_leetcode.ListNode;
-
-/*
- * Definition for singly-linked list.
- * class ListNode {
- * int val;
- * ListNode next;
- * ListNode(int x) {
- * val = x;
- * next = null;
- * }
- * }
- */
-public class Solution {
- private ListNode forward;
-
- public void reorderList(ListNode head) {
- forward = head;
- dfs(head);
- }
-
- private void dfs(ListNode node) {
- if (node != null) {
- dfs(node.next);
- if (forward != null) {
- ListNode next = forward.next;
- // even case: forward.next coincide with node
- if (next == node) {
- node.next = null;
- } else {
- node.next = next;
- }
- forward.next = node;
- forward = node.next;
- }
- // odd case: forward coincide with node
- if (forward == node) {
- forward.next = null;
- forward = forward.next;
- }
- }
- }
-}
diff --git a/src.save/main/java/g0101_0200/s0144_binary_tree_preorder_traversal/Solution.java b/src.save/main/java/g0101_0200/s0144_binary_tree_preorder_traversal/Solution.java
deleted file mode 100644
index a91faa407..000000000
--- a/src.save/main/java/g0101_0200/s0144_binary_tree_preorder_traversal/Solution.java
+++ /dev/null
@@ -1,45 +0,0 @@
-package g0101_0200.s0144_binary_tree_preorder_traversal;
-
-// #Easy #Depth_First_Search #Tree #Binary_Tree #Stack #Data_Structure_I_Day_10_Tree
-// #2022_02_23_Time_1_ms_(42.23%)_Space_42.4_MB_(12.48%)
-
-import com_github_leetcode.TreeNode;
-import java.util.ArrayList;
-import java.util.List;
-import java.util.Stack;
-
-/*
- * Definition for a binary tree node.
- * public class TreeNode {
- * int val;
- * TreeNode left;
- * TreeNode right;
- * TreeNode() {}
- * TreeNode(int val) { this.val = val; }
- * TreeNode(int val, TreeNode left, TreeNode right) {
- * this.val = val;
- * this.left = left;
- * this.right = right;
- * }
- * }
- */
-@SuppressWarnings("java:S1149")
-public class Solution {
- public List preorderTraversal(TreeNode root) {
- List result = new ArrayList<>();
- if (root == null) {
- return result;
- }
- Stack stack = new Stack<>();
- TreeNode current = root;
- while (current != null || !stack.isEmpty()) {
- while (current != null) {
- result.add(current.val);
- stack.push(current.right);
- current = current.left;
- }
- current = stack.pop();
- }
- return result;
- }
-}
diff --git a/src.save/main/java/g0101_0200/s0145_binary_tree_postorder_traversal/Solution.java b/src.save/main/java/g0101_0200/s0145_binary_tree_postorder_traversal/Solution.java
deleted file mode 100644
index 6af0b295c..000000000
--- a/src.save/main/java/g0101_0200/s0145_binary_tree_postorder_traversal/Solution.java
+++ /dev/null
@@ -1,35 +0,0 @@
-package g0101_0200.s0145_binary_tree_postorder_traversal;
-
-// #Easy #Depth_First_Search #Tree #Binary_Tree #Stack #Data_Structure_I_Day_10_Tree
-// #2022_02_23_Time_1_ms_(42.74%)_Space_42.2_MB_(23.81%)
-
-import com_github_leetcode.TreeNode;
-import java.util.ArrayList;
-import java.util.List;
-
-/*
- * Definition for a binary tree node.
- * public class TreeNode {
- * int val;
- * TreeNode left;
- * TreeNode right;
- * TreeNode() {}
- * TreeNode(int val) { this.val = val; }
- * TreeNode(int val, TreeNode left, TreeNode right) {
- * this.val = val;
- * this.left = left;
- * this.right = right;
- * }
- * }
- */
-public class Solution {
- public List postorderTraversal(TreeNode root) {
- if (root == null) {
- return new ArrayList<>();
- }
- List res = postorderTraversal(root.left);
- res.addAll(postorderTraversal(root.right));
- res.add(root.val);
- return res;
- }
-}
diff --git a/src.save/main/java/g0101_0200/s0146_lru_cache/LruCache.java b/src.save/main/java/g0101_0200/s0146_lru_cache/LruCache.java
deleted file mode 100644
index 22c4723a4..000000000
--- a/src.save/main/java/g0101_0200/s0146_lru_cache/LruCache.java
+++ /dev/null
@@ -1,122 +0,0 @@
-package g0101_0200.s0146_lru_cache;
-
-// #Medium #Top_100_Liked_Questions #Top_Interview_Questions #Hash_Table #Design #Linked_List
-// #Doubly_Linked_List #2022_02_23_Time_82_ms_(59.12%)_Space_124.8_MB_(63.96%)
-
-import java.util.HashMap;
-import java.util.Map;
-
-public class LruCache {
- private static class LruCacheNode {
- int key;
- int value;
- LruCacheNode prev;
- LruCacheNode next;
-
- public LruCacheNode(int k, int v) {
- key = k;
- value = v;
- }
- }
-
- private int capacity;
- private Map cacheMap = new HashMap<>();
- // insert here
- private LruCacheNode head;
- // remove here
- private LruCacheNode tail;
-
- public LruCache(int cap) {
- capacity = cap;
- }
-
- public int get(int key) {
- LruCacheNode val = cacheMap.get(key);
- if (val == null) {
- return -1;
- }
- moveToHead(val);
- return val.value;
- }
-
- /*
- * Scenarios :
- * 1. Value key is already present.
- * update
- * move node to head
- * 2. cache is not full
- * cache is empty (create node and assign head and tail)
- * cache is partially empty (add node to head and update head pointer)
- * 3. cache is full
- * remove node at tail, update head, tail pointers
- * Recursively call put
- *
- *
- * move node to head Scenarios
- * 1. node is at head
- * 2. node is at tail
- * 3. node is in middle
- *
- */
- public void put(int key, int value) {
- LruCacheNode valNode = cacheMap.get(key);
- if (valNode != null) {
- valNode.value = value;
- moveToHead(valNode);
- } else {
- if (cacheMap.size() < capacity) {
- if (cacheMap.size() == 0) {
- LruCacheNode node = new LruCacheNode(key, value);
- cacheMap.put(key, node);
- head = node;
- tail = node;
- } else {
- LruCacheNode node = new LruCacheNode(key, value);
- cacheMap.put(key, node);
- node.next = head;
- head.prev = node;
- head = node;
- }
- } else {
- // remove from tail
- LruCacheNode last = tail;
- tail = last.prev;
- if (tail != null) {
- tail.next = null;
- }
- cacheMap.remove(last.key);
- if (cacheMap.size() == 0) {
- head = null;
- }
- // Call recursively
- put(key, value);
- }
- }
- }
-
- /*
- * check for 3 conditions
- * 1. node is already at head
- * 2. Node is tail node
- * 3. Node in middle node
- */
- private void moveToHead(LruCacheNode node) {
- if (node == head) {
- return;
- }
- if (node == tail) {
- tail = node.prev;
- }
- // node is not head, it should have some valid prev node
- LruCacheNode prev = node.prev;
- LruCacheNode next = node.next;
- prev.next = next;
- if (next != null) {
- next.prev = prev;
- }
- node.prev = null;
- node.next = head;
- head.prev = node;
- head = node;
- }
-}
diff --git a/src.save/main/java/g0101_0200/s0147_insertion_sort_list/Solution.java b/src.save/main/java/g0101_0200/s0147_insertion_sort_list/Solution.java
deleted file mode 100644
index 3c33af2ba..000000000
--- a/src.save/main/java/g0101_0200/s0147_insertion_sort_list/Solution.java
+++ /dev/null
@@ -1,41 +0,0 @@
-package g0101_0200.s0147_insertion_sort_list;
-
-// #Medium #Sorting #Linked_List #2022_02_23_Time_3_ms_(92.25%)_Space_45.8_MB_(5.45%)
-
-import com_github_leetcode.ListNode;
-import java.util.Arrays;
-
-/*
- * Definition for singly-linked list.
- * public class ListNode {
- * int val;
- * ListNode next;
- * ListNode() {}
- * ListNode(int val) { this.val = val; }
- * ListNode(int val, ListNode next) { this.val = val; this.next = next; }
- * }
- */
-public class Solution {
- public ListNode insertionSortList(ListNode head) {
- ListNode tnode = head;
- ListNode res = null;
- int count = 0;
- while (tnode != null) {
- count++;
- tnode = tnode.next;
- }
- int[] nums = new int[count];
- for (int i = 0; i < count; i++) {
- nums[i] = head.val;
- head = head.next;
- }
- Arrays.sort(nums);
- for (int i = nums.length - 1; i >= 0; i--) {
- ListNode temp = new ListNode();
- temp.val = nums[i];
- temp.next = res;
- res = temp;
- }
- return res;
- }
-}
diff --git a/src.save/main/java/g0101_0200/s0148_sort_list/Solution.java b/src.save/main/java/g0101_0200/s0148_sort_list/Solution.java
deleted file mode 100644
index a3c1667e6..000000000
--- a/src.save/main/java/g0101_0200/s0148_sort_list/Solution.java
+++ /dev/null
@@ -1,56 +0,0 @@
-package g0101_0200.s0148_sort_list;
-
-// #Medium #Top_100_Liked_Questions #Top_Interview_Questions #Sorting #Two_Pointers #Linked_List
-// #Divide_and_Conquer #Merge_Sort #2022_02_23_Time_8_ms_(78.95%)_Space_57.2_MB_(18.69%)
-
-import com_github_leetcode.ListNode;
-
-/*
- * Definition for singly-linked list.
- * public class ListNode {
- * int val;
- * ListNode next;
- * ListNode() {}
- * ListNode(int val) { this.val = val; }
- * ListNode(int val, ListNode next) { this.val = val; this.next = next; }
- * }
- */
-@SuppressWarnings("java:S135")
-public class Solution {
- public ListNode sortList(ListNode head) {
- if (head == null || head.next == null) {
- return head;
- }
- ListNode slow = head;
- ListNode fast = head;
- ListNode pre = slow;
- while (fast != null && fast.next != null) {
- pre = slow;
- slow = slow.next;
- fast = fast.next.next;
- }
- pre.next = null;
- ListNode first = sortList(head);
- ListNode second = sortList(slow);
- ListNode res = new ListNode(1);
- ListNode cur = res;
- while (first != null || second != null) {
- if (first == null) {
- cur.next = second;
- break;
- } else if (second == null) {
- cur.next = first;
- break;
- } else if (first.val <= second.val) {
- cur.next = first;
- first = first.next;
- cur = cur.next;
- } else {
- cur.next = second;
- second = second.next;
- cur = cur.next;
- }
- }
- return res.next;
- }
-}
diff --git a/src.save/main/java/g0101_0200/s0149_max_points_on_a_line/Solution.java b/src.save/main/java/g0101_0200/s0149_max_points_on_a_line/Solution.java
deleted file mode 100644
index 30b1fcd82..000000000
--- a/src.save/main/java/g0101_0200/s0149_max_points_on_a_line/Solution.java
+++ /dev/null
@@ -1,28 +0,0 @@
-package g0101_0200.s0149_max_points_on_a_line;
-
-// #Hard #Top_Interview_Questions #Hash_Table #Math #Geometry
-// #2022_02_23_Time_4_ms_(98.44%)_Space_41.3_MB_(61.51%)
-
-public class Solution {
- public int maxPoints(int[][] points) {
- if (points.length < 2) {
- return points.length;
- }
- int max = 0;
- for (int i = 0; i < points.length; i++) {
- for (int j = i + 1; j < points.length; j++) {
- int x = points[j][0] - points[i][0];
- int y = points[j][1] - points[i][1];
- int c = x * points[j][1] - y * points[j][0];
- int count = 2;
- for (int k = j + 1; k < points.length; k++) {
- if (c == x * points[k][1] - y * points[k][0]) {
- count++;
- }
- }
- max = Math.max(count, max);
- }
- }
- return max;
- }
-}
diff --git a/src.save/main/java/g0101_0200/s0150_evaluate_reverse_polish_notation/Solution.java b/src.save/main/java/g0101_0200/s0150_evaluate_reverse_polish_notation/Solution.java
deleted file mode 100644
index 3f11fad3a..000000000
--- a/src.save/main/java/g0101_0200/s0150_evaluate_reverse_polish_notation/Solution.java
+++ /dev/null
@@ -1,34 +0,0 @@
-package g0101_0200.s0150_evaluate_reverse_polish_notation;
-
-// #Medium #Top_Interview_Questions #Array #Math #Stack
-// #2022_02_23_Time_12_ms_(29.56%)_Space_44.8_MB_(8.19%)
-
-import java.util.Stack;
-
-@SuppressWarnings("java:S1149")
-public class Solution {
- public int evalRPN(String[] tokens) {
- Stack st = new Stack<>();
- for (String token : tokens) {
- if (!Character.isDigit(token.charAt(token.length() - 1))) {
- st.push(eval(st.pop(), st.pop(), token));
- } else {
- st.push(Integer.parseInt(token));
- }
- }
- return st.pop();
- }
-
- private int eval(int second, int first, String operator) {
- switch (operator) {
- case "+":
- return first + second;
- case "-":
- return first - second;
- case "*":
- return first * second;
- default:
- return first / second;
- }
- }
-}
diff --git a/src.save/main/java/g0101_0200/s0151_reverse_words_in_a_string/Solution.java b/src.save/main/java/g0101_0200/s0151_reverse_words_in_a_string/Solution.java
deleted file mode 100644
index bd9da929d..000000000
--- a/src.save/main/java/g0101_0200/s0151_reverse_words_in_a_string/Solution.java
+++ /dev/null
@@ -1,25 +0,0 @@
-package g0101_0200.s0151_reverse_words_in_a_string;
-
-// #Medium #String #Two_Pointers #2022_02_23_Time_3_ms_(96.37%)_Space_43.4_MB_(35.43%)
-
-public class Solution {
- public String reverseWords(String s) {
- StringBuilder sb = new StringBuilder();
- int i = s.length() - 1;
- while (i >= 0) {
- if (s.charAt(i) == ' ') {
- i--;
- continue;
- }
- int start = s.lastIndexOf(' ', i);
- sb.append(' ');
- sb.append(s, start + 1, i + 1);
- i = start - 1;
- }
- if (sb.length() > 0) {
- sb.deleteCharAt(0);
- }
-
- return sb.toString();
- }
-}
diff --git a/src.save/main/java/g0101_0200/s0152_maximum_product_subarray/Solution.java b/src.save/main/java/g0101_0200/s0152_maximum_product_subarray/Solution.java
deleted file mode 100644
index 3067acba4..000000000
--- a/src.save/main/java/g0101_0200/s0152_maximum_product_subarray/Solution.java
+++ /dev/null
@@ -1,27 +0,0 @@
-package g0101_0200.s0152_maximum_product_subarray;
-
-// #Medium #Top_100_Liked_Questions #Top_Interview_Questions #Array #Dynamic_Programming
-// #Dynamic_Programming_I_Day_6 #2022_02_23_Time_0_ms_(100.00%)_Space_42.5_MB_(38.69%)
-
-public class Solution {
- public int maxProduct(int[] arr) {
- int ans = Integer.MIN_VALUE;
- int cprod = 1;
- for (int j : arr) {
- cprod = cprod * j;
- ans = Math.max(ans, cprod);
- if (cprod == 0) {
- cprod = 1;
- }
- }
- cprod = 1;
- for (int i = arr.length - 1; i >= 0; i--) {
- cprod = cprod * arr[i];
- ans = Math.max(ans, cprod);
- if (cprod == 0) {
- cprod = 1;
- }
- }
- return ans;
- }
-}
diff --git a/src.save/main/java/g0101_0200/s0153_find_minimum_in_rotated_sorted_array/Solution.java b/src.save/main/java/g0101_0200/s0153_find_minimum_in_rotated_sorted_array/Solution.java
deleted file mode 100644
index 3bf2d839c..000000000
--- a/src.save/main/java/g0101_0200/s0153_find_minimum_in_rotated_sorted_array/Solution.java
+++ /dev/null
@@ -1,30 +0,0 @@
-package g0101_0200.s0153_find_minimum_in_rotated_sorted_array;
-
-// #Medium #Array #Binary_Search #2022_02_23_Time_0_ms_(100.00%)_Space_41.9_MB_(37.13%)
-
-public class Solution {
- private int findMinUtil(int[] nums, int l, int r) {
- if (l == r) {
- return nums[l];
- }
- int mid = (l + r) / 2;
- if (mid == l && nums[mid] < nums[r]) {
- return nums[l];
- }
- if (mid - 1 >= 0 && nums[mid - 1] > nums[mid]) {
- return nums[mid];
- }
- if (nums[mid] < nums[l]) {
- return findMinUtil(nums, l, mid - 1);
- } else if (nums[mid] > nums[r]) {
- return findMinUtil(nums, mid + 1, r);
- }
- return findMinUtil(nums, l, mid - 1);
- }
-
- public int findMin(int[] nums) {
- int l = 0;
- int r = nums.length - 1;
- return findMinUtil(nums, l, r);
- }
-}
diff --git a/src.save/main/java/g0101_0200/s0154_find_minimum_in_rotated_sorted_array_ii/Solution.java b/src.save/main/java/g0101_0200/s0154_find_minimum_in_rotated_sorted_array_ii/Solution.java
deleted file mode 100644
index b57db38d8..000000000
--- a/src.save/main/java/g0101_0200/s0154_find_minimum_in_rotated_sorted_array_ii/Solution.java
+++ /dev/null
@@ -1,31 +0,0 @@
-package g0101_0200.s0154_find_minimum_in_rotated_sorted_array_ii;
-
-// #Hard #Array #Binary_Search #2022_02_23_Time_0_ms_(100.00%)_Space_41.8_MB_(40.58%)
-
-public class Solution {
- public int findMin(int[] nums) {
- if (nums == null || nums.length == 0) {
- return 0;
- }
- return find(0, nums.length - 1, nums);
- }
-
- private int find(int left, int right, int[] nums) {
- if (left + 1 >= right) {
- return Math.min(nums[left], nums[right]);
- }
- int mid = left + (right - left) / 2;
- if (nums[left] == nums[right] && nums[left] == nums[mid]) {
- return Math.min(find(left, mid, nums), find(mid, right, nums));
- }
- if (nums[left] >= nums[right]) {
- if (nums[mid] >= nums[left]) {
- return find(mid, right, nums);
- } else {
- return find(left, mid, nums);
- }
- } else {
- return find(left, mid, nums);
- }
- }
-}
diff --git a/src.save/main/java/g0101_0200/s0155_min_stack/MinStack.java b/src.save/main/java/g0101_0200/s0155_min_stack/MinStack.java
deleted file mode 100644
index e06e30324..000000000
--- a/src.save/main/java/g0101_0200/s0155_min_stack/MinStack.java
+++ /dev/null
@@ -1,43 +0,0 @@
-package g0101_0200.s0155_min_stack;
-
-// #Easy #Top_100_Liked_Questions #Top_Interview_Questions #Stack #Design
-// #Data_Structure_II_Day_14_Stack_Queue #2022_02_23_Time_5_ms_(81.77%)_Space_48.5_MB_(20.01%)
-
-public class MinStack {
- private Node currentNode;
-
- // initialize your data structure here.
- public MinStack() {
- // no initialization needed.
- }
-
- public void push(int val) {
- if (currentNode == null) {
- currentNode = new Node(val, val, null, null);
- } else {
- currentNode.nextNode = new Node(Math.min(currentNode.min, val), val, currentNode, null);
- currentNode = currentNode.nextNode;
- }
- }
-
- public void pop() {
- currentNode = currentNode.previousNode;
- }
-
- public int top() {
- return currentNode.data;
- }
-
- public int getMin() {
- return currentNode.min;
- }
-}
-
-/*
- * Your MinStack object will be instantiated and called as such:
- * MinStack obj = new MinStack();
- * obj.push(val);
- * obj.pop();
- * int param_3 = obj.top();
- * int param_4 = obj.getMin();
- */
diff --git a/src.save/main/java/g0101_0200/s0155_min_stack/Node.java b/src.save/main/java/g0101_0200/s0155_min_stack/Node.java
deleted file mode 100644
index 35e9f91cf..000000000
--- a/src.save/main/java/g0101_0200/s0155_min_stack/Node.java
+++ /dev/null
@@ -1,18 +0,0 @@
-package g0101_0200.s0155_min_stack;
-
-// #Easy #Top_100_Liked_Questions #Top_Interview_Questions #Stack #Design
-// #Data_Structure_II_Day_14_Stack_Queue #2022_02_23_Time_5_ms_(81.77%)_Space_48.5_MB_(20.01%)
-
-public class Node {
- int min;
- int data;
- Node nextNode;
- Node previousNode;
-
- public Node(int min, int data, Node previousNode, Node nextNode) {
- this.min = min;
- this.data = data;
- this.previousNode = previousNode;
- this.nextNode = nextNode;
- }
-}
diff --git a/src.save/main/java/g0101_0200/s0160_intersection_of_two_linked_lists/Solution.java b/src.save/main/java/g0101_0200/s0160_intersection_of_two_linked_lists/Solution.java
deleted file mode 100644
index 3965a25ac..000000000
--- a/src.save/main/java/g0101_0200/s0160_intersection_of_two_linked_lists/Solution.java
+++ /dev/null
@@ -1,19 +0,0 @@
-package g0101_0200.s0160_intersection_of_two_linked_lists;
-
-// #Easy #Top_100_Liked_Questions #Top_Interview_Questions #Hash_Table #Two_Pointers #Linked_List
-// #Data_Structure_II_Day_11_Linked_List #2022_02_23_Time_2_ms_(61.05%)_Space_55.1_MB_(26.21%)
-
-import com_github_leetcode.ListNode;
-
-@SuppressWarnings("java:S2583")
-public class Solution {
- public ListNode getIntersectionNode(ListNode headA, ListNode headB) {
- ListNode node1 = headA;
- ListNode node2 = headB;
- while (node1 != node2) {
- node1 = node1 == null ? headB : node1.next;
- node2 = node2 == null ? headA : node2.next;
- }
- return node1;
- }
-}
diff --git a/src.save/main/java/g0101_0200/s0162_find_peak_element/Solution.java b/src.save/main/java/g0101_0200/s0162_find_peak_element/Solution.java
deleted file mode 100644
index 2c7913434..000000000
--- a/src.save/main/java/g0101_0200/s0162_find_peak_element/Solution.java
+++ /dev/null
@@ -1,25 +0,0 @@
-package g0101_0200.s0162_find_peak_element;
-
-// #Medium #Top_Interview_Questions #Array #Binary_Search #Algorithm_II_Day_2_Binary_Search
-// #2022_03_04_Time_0_ms_(100.00%)_Space_43.1_MB_(21.18%)
-
-public class Solution {
- public int findPeakElement(int[] nums) {
- int start = 0;
- int end = nums.length - 1;
-
- while (start < end) {
- // This is done because start and end might be big numbers, so it might exceed the
- // integer limit.
- int mid = start + ((end - start) / 2);
-
- if (nums[mid + 1] > nums[mid]) {
- start = mid + 1;
- } else {
- end = mid;
- }
- }
-
- return start;
- }
-}
diff --git a/src.save/main/java/g0101_0200/s0164_maximum_gap/Solution.java b/src.save/main/java/g0101_0200/s0164_maximum_gap/Solution.java
deleted file mode 100644
index 6a28168bc..000000000
--- a/src.save/main/java/g0101_0200/s0164_maximum_gap/Solution.java
+++ /dev/null
@@ -1,26 +0,0 @@
-package g0101_0200.s0164_maximum_gap;
-
-// #Hard #Array #Sorting #Bucket_Sort #Radix_Sort
-// #2022_03_04_Time_36_ms_(66.54%)_Space_55.6_MB_(79.55%)
-
-import java.util.Arrays;
-
-public class Solution {
- public int maximumGap(int[] nums) {
- if (nums.length < 2) {
- return 0;
- }
-
- int ret = Integer.MIN_VALUE;
-
- Arrays.sort(nums);
-
- for (int i = 0; i < nums.length - 1; i++) {
- if ((nums[i + 1] - nums[i]) > ret) {
- ret = (nums[i + 1] - nums[i]);
- }
- }
-
- return ret;
- }
-}
diff --git a/src.save/main/java/g0101_0200/s0165_compare_version_numbers/Solution.java b/src.save/main/java/g0101_0200/s0165_compare_version_numbers/Solution.java
deleted file mode 100644
index 34b04bab2..000000000
--- a/src.save/main/java/g0101_0200/s0165_compare_version_numbers/Solution.java
+++ /dev/null
@@ -1,52 +0,0 @@
-package g0101_0200.s0165_compare_version_numbers;
-
-// #Medium #String #Two_Pointers #2022_03_04_Time_1_ms_(90.80%)_Space_42.2_MB_(39.21%)
-
-public class Solution {
- public int compareVersion(String version1, String version2) {
- // acquire first number
- int numA = 0;
- int i;
- for (i = 0; i < version1.length(); i++) {
- char c = version1.charAt(i);
- if (c == '.') {
- break;
- } else {
- numA = numA * 10 + (c - 48);
- }
- }
- // acquire second number
- int numB = 0;
- int j;
- for (j = 0; j < version2.length(); j++) {
- char c = version2.charAt(j);
- if (c == '.') {
- break;
- } else {
- numB = numB * 10 + (c - 48);
- }
- }
- // compare
- if (numA > numB) {
- return 1;
- } else if (numA < numB) {
- return -1;
- } else {
- // equal
- String v1 = "";
- String v2 = "";
- if (i != version1.length()) {
- v1 = version1.substring(i + 1);
- }
- if (j != version2.length()) {
- v2 = version2.substring(j + 1);
- }
- // if both versions end here, they are equal
- if (v1.equals("") && v2.equals("")) {
- return 0;
- } else {
- return compareVersion(v1, v2);
- }
- }
- }
-}
diff --git a/src.save/main/java/g0101_0200/s0166_fraction_to_recurring_decimal/Solution.java b/src.save/main/java/g0101_0200/s0166_fraction_to_recurring_decimal/Solution.java
deleted file mode 100644
index 1344632ce..000000000
--- a/src.save/main/java/g0101_0200/s0166_fraction_to_recurring_decimal/Solution.java
+++ /dev/null
@@ -1,46 +0,0 @@
-package g0101_0200.s0166_fraction_to_recurring_decimal;
-
-// #Medium #Top_Interview_Questions #String #Hash_Table #Math
-// #2022_03_04_Time_4_ms_(33.10%)_Space_41.6_MB_(26.44%)
-
-import java.util.HashMap;
-import java.util.Map;
-
-@SuppressWarnings("java:S2153")
-public class Solution {
- public String fractionToDecimal(int numerator, int denominator) {
- if (numerator == 0) {
- return "0";
- }
- StringBuilder sb = new StringBuilder();
- // negative case
- if (numerator > 0 && denominator < 0 || numerator < 0 && denominator > 0) {
- sb.append("-");
- }
- long x = Math.abs(Long.valueOf(numerator));
- long y = Math.abs(Long.valueOf(denominator));
- sb.append(x / y);
- long remainder = x % y;
- if (remainder == 0) {
- return sb.toString();
- }
- // decimal case
- sb.append(".");
- // store the remainder in a Hashmap because in the case of recurring decimal, the remainder
- // repeats as dividend.
- Map map = new HashMap<>();
- while (remainder != 0) {
- if (map.containsKey(remainder)) {
- sb.insert(map.get(remainder), "(");
- sb.append(")");
- break;
- }
- // store the remainder and the index of it's occurence in the String
- map.put(remainder, sb.length());
- remainder *= 10;
- sb.append(remainder / y);
- remainder %= y;
- }
- return sb.toString();
- }
-}
diff --git a/src.save/main/java/g0101_0200/s0167_two_sum_ii_input_array_is_sorted/Solution.java b/src.save/main/java/g0101_0200/s0167_two_sum_ii_input_array_is_sorted/Solution.java
deleted file mode 100644
index edc7152a9..000000000
--- a/src.save/main/java/g0101_0200/s0167_two_sum_ii_input_array_is_sorted/Solution.java
+++ /dev/null
@@ -1,26 +0,0 @@
-package g0101_0200.s0167_two_sum_ii_input_array_is_sorted;
-
-// #Easy #Array #Binary_Search #Two_Pointers #Algorithm_I_Day_3_Two_Pointers
-// #2022_03_04_Time_2_ms_(49.88%)_Space_49.8_MB_(25.20%)
-
-public class Solution {
- public int[] twoSum(int[] numbers, int target) {
- int[] res = new int[2];
- int i = 0;
- int j = numbers.length - 1;
-
- while (i < j) {
- int sum = numbers[i] + numbers[j];
- if (sum == target) {
- res[0] = i + 1;
- res[1] = j + 1;
- return res;
- } else if (sum < target) {
- i++;
- } else {
- j--;
- }
- }
- return res;
- }
-}
diff --git a/src.save/main/java/g0101_0200/s0168_excel_sheet_column_title/Solution.java b/src.save/main/java/g0101_0200/s0168_excel_sheet_column_title/Solution.java
deleted file mode 100644
index f5b26f53d..000000000
--- a/src.save/main/java/g0101_0200/s0168_excel_sheet_column_title/Solution.java
+++ /dev/null
@@ -1,21 +0,0 @@
-package g0101_0200.s0168_excel_sheet_column_title;
-
-// #Easy #String #Math #2022_03_04_Time_0_ms_(100.00%)_Space_40.7_MB_(51.16%)
-
-public class Solution {
- public String convertToTitle(int n) {
- StringBuilder sb = new StringBuilder();
- while (n != 0) {
- int remainder = n % 26;
- if (remainder == 0) {
- remainder += 26;
- }
- if (n >= remainder) {
- n -= remainder;
- sb.append((char) (remainder + 64));
- }
- n /= 26;
- }
- return sb.reverse().toString();
- }
-}
diff --git a/src.save/main/java/g0101_0200/s0169_majority_element/Solution.java b/src.save/main/java/g0101_0200/s0169_majority_element/Solution.java
deleted file mode 100644
index a7c518119..000000000
--- a/src.save/main/java/g0101_0200/s0169_majority_element/Solution.java
+++ /dev/null
@@ -1,38 +0,0 @@
-package g0101_0200.s0169_majority_element;
-
-// #Easy #Top_100_Liked_Questions #Top_Interview_Questions #Array #Hash_Table #Sorting #Counting
-// #Divide_and_Conquer #Data_Structure_II_Day_1_Array
-// #2022_03_04_Time_2_ms_(83.81%)_Space_56.6_MB_(22.94%)
-
-public class Solution {
- public int majorityElement(int[] arr) {
- int count = 1;
- int majority = arr[0];
- // For Potential Majority Element
- for (int i = 1; i < arr.length; i++) {
- if (arr[i] == majority) {
- count++;
- } else {
- if (count > 1) {
- count--;
- } else {
- majority = arr[i];
- }
- }
- }
-
- // For Confirmation
- count = 0;
- for (int j : arr) {
- if (j == majority) {
- count++;
- }
- }
-
- if (count >= (arr.length / 2) + 1) {
- return majority;
- } else {
- return -1;
- }
- }
-}
diff --git a/src.save/main/java/g0101_0200/s0171_excel_sheet_column_number/Solution.java b/src.save/main/java/g0101_0200/s0171_excel_sheet_column_number/Solution.java
deleted file mode 100644
index fbd746db2..000000000
--- a/src.save/main/java/g0101_0200/s0171_excel_sheet_column_number/Solution.java
+++ /dev/null
@@ -1,15 +0,0 @@
-package g0101_0200.s0171_excel_sheet_column_number;
-
-// #Easy #Top_Interview_Questions #String #Math
-// #2022_03_04_Time_3_ms_(24.67%)_Space_43.1_MB_(24.41%)
-
-public class Solution {
- public int titleToNumber(String s) {
- int num = 0;
- int pow = 0;
- for (int i = s.length() - 1; i >= 0; i--) {
- num += (int) Math.pow(26, pow++) * (s.charAt(i) - 'A' + 1);
- }
- return num;
- }
-}
diff --git a/src.save/main/java/g0101_0200/s0172_factorial_trailing_zeroes/Solution.java b/src.save/main/java/g0101_0200/s0172_factorial_trailing_zeroes/Solution.java
deleted file mode 100644
index e052b5170..000000000
--- a/src.save/main/java/g0101_0200/s0172_factorial_trailing_zeroes/Solution.java
+++ /dev/null
@@ -1,15 +0,0 @@
-package g0101_0200.s0172_factorial_trailing_zeroes;
-
-// #Medium #Top_Interview_Questions #Math #2022_03_04_Time_1_ms_(81.96%)_Space_41.8_MB_(6.69%)
-
-public class Solution {
- public int trailingZeroes(int n) {
- int base = 5;
- int count = 0;
- while (n >= base) {
- count += n / base;
- base = base * 5;
- }
- return count;
- }
-}
diff --git a/src.save/main/java/g0101_0200/s0174_dungeon_game/Solution.java b/src.save/main/java/g0101_0200/s0174_dungeon_game/Solution.java
deleted file mode 100644
index 849f700d7..000000000
--- a/src.save/main/java/g0101_0200/s0174_dungeon_game/Solution.java
+++ /dev/null
@@ -1,31 +0,0 @@
-package g0101_0200.s0174_dungeon_game;
-
-// #Hard #Array #Dynamic_Programming #Matrix #2022_03_04_Time_1_ms_(96.60%)_Space_44.5_MB_(13.03%)
-
-public class Solution {
- public int calculateMinimumHP(int[][] dungeon) {
- int m = dungeon.length;
- int n = dungeon[0].length;
- int[][] memo = new int[m][n];
- return Math.max(1, 1 - traverse(dungeon, 0, 0, memo));
- }
-
- private int traverse(int[][] dungeon, int r, int c, int[][] memo) {
- if (r == dungeon.length - 1 && c == dungeon[0].length - 1) {
- return dungeon[r][c];
- }
- if (memo[r][c] != 0) {
- return memo[r][c];
- }
- int res = Integer.MIN_VALUE;
- if (r + 1 < dungeon.length) {
- res = Math.max(res, traverse(dungeon, r + 1, c, memo));
- }
- if (c + 1 < dungeon[0].length) {
- res = Math.max(res, traverse(dungeon, r, c + 1, memo));
- }
- res = Math.min(dungeon[r][c], res + dungeon[r][c]);
- memo[r][c] = res;
- return res;
- }
-}
diff --git a/src.save/main/java/g0101_0200/s0175_combine_two_tables/script.sql b/src.save/main/java/g0101_0200/s0175_combine_two_tables/script.sql
deleted file mode 100644
index c9d6e8081..000000000
--- a/src.save/main/java/g0101_0200/s0175_combine_two_tables/script.sql
+++ /dev/null
@@ -1,4 +0,0 @@
-# Write your MySQL query statement below
-# #Easy #Database #2022_03_04_Time_449_ms_(30.35%)_Space_0B_(100.00%)
-SELECT FirstName, LastName, City, State
-FROM Person LEFT JOIN Address USING (PersonId)
\ No newline at end of file
diff --git a/src.save/main/java/g0101_0200/s0176_second_highest_salary/script.sql b/src.save/main/java/g0101_0200/s0176_second_highest_salary/script.sql
deleted file mode 100644
index 53a6a4680..000000000
--- a/src.save/main/java/g0101_0200/s0176_second_highest_salary/script.sql
+++ /dev/null
@@ -1,8 +0,0 @@
-# Write your MySQL query statement below
-# #Medium #Database #2022_03_04_Time_203_ms_(63.47%)_Space_0B_(100.00%)
-SELECT ifnull(
- (SELECT distinct(Salary)
- FROM Employee
- ORDER BY Salary DESC
- LIMIT 1
- OFFSET 1), NULL) SecondHighestSalary;
\ No newline at end of file
diff --git a/src.save/main/java/g0101_0200/s0177_nth_highest_salary/script.sql b/src.save/main/java/g0101_0200/s0177_nth_highest_salary/script.sql
deleted file mode 100644
index f353ff1c5..000000000
--- a/src.save/main/java/g0101_0200/s0177_nth_highest_salary/script.sql
+++ /dev/null
@@ -1,10 +0,0 @@
-CREATE FUNCTION getNthHighestSalary(N INT) RETURNS INT
-BEGIN
-DECLARE M INT;
-SET M=N-1;
- RETURN (
- # Write your MySQL query statement below.
- # #Medium #Database #2022_03_04_Time_328_ms_(65.32%)_Space_0B_(100.00%)
- SELECT DISTINCT Salary FROM Employee ORDER BY Salary DESC LIMIT M, 1
- );
-END
\ No newline at end of file
diff --git a/src.save/main/java/g0101_0200/s0178_rank_scores/script.sql b/src.save/main/java/g0101_0200/s0178_rank_scores/script.sql
deleted file mode 100644
index d85a7ce8a..000000000
--- a/src.save/main/java/g0101_0200/s0178_rank_scores/script.sql
+++ /dev/null
@@ -1,4 +0,0 @@
-# Write your MySQL query statement below
-# #Medium #Database #2022_03_04_Time_299_ms_(52.08%)_Space_0B_(100.00%)
-select Score, DENSE_RANK() OVER(order by Score Desc) as "Rank" from Scores order by "Rank" Asc;
-
diff --git a/src.save/main/java/g0101_0200/s0179_largest_number/Solution.java b/src.save/main/java/g0101_0200/s0179_largest_number/Solution.java
deleted file mode 100644
index 59efa0ca9..000000000
--- a/src.save/main/java/g0101_0200/s0179_largest_number/Solution.java
+++ /dev/null
@@ -1,23 +0,0 @@
-package g0101_0200.s0179_largest_number;
-
-// #Medium #Top_Interview_Questions #String #Sorting #Greedy
-// #2022_03_04_Time_11_ms_(45.93%)_Space_43.3_MB_(49.01%)
-
-import java.util.Arrays;
-
-public class Solution {
- public String largestNumber(int[] nums) {
- int n = nums.length;
- String[] s = new String[n];
- for (int i = 0; i < n; i++) {
- s[i] = String.valueOf(nums[i]);
- }
- Arrays.sort(s, (a, b) -> (b + a).compareTo(a + b));
- StringBuilder sb = new StringBuilder();
- for (String str : s) {
- sb.append(str);
- }
- String result = sb.toString();
- return result.startsWith("0") ? "0" : result;
- }
-}
diff --git a/src.save/main/java/g0101_0200/s0180_consecutive_numbers/script.sql b/src.save/main/java/g0101_0200/s0180_consecutive_numbers/script.sql
deleted file mode 100644
index d6de1a66a..000000000
--- a/src.save/main/java/g0101_0200/s0180_consecutive_numbers/script.sql
+++ /dev/null
@@ -1,6 +0,0 @@
-# Write your MySQL query statement below
-# #Medium #Database #2022_03_04_Time_636_ms_(19.31%)_Space_0B_(100.00%)
-select distinct num as ConsecutiveNums from
-(select num, lag(num,1) over(order by id) as l1, lag(num,2) over(order by id) as l2
-from Logs) con_thr
-where num = l1 and num = l2
\ No newline at end of file
diff --git a/src.save/main/java/g0101_0200/s0181_employees_earning_more_than_their_managers/script.sql b/src.save/main/java/g0101_0200/s0181_employees_earning_more_than_their_managers/script.sql
deleted file mode 100644
index 1bf3c4b32..000000000
--- a/src.save/main/java/g0101_0200/s0181_employees_earning_more_than_their_managers/script.sql
+++ /dev/null
@@ -1,4 +0,0 @@
-# Write your MySQL query statement below
-# #Easy #Database #2022_03_04_Time_385_ms_(52.30%)_Space_0B_(100.00%)
-select a.Name as Employee from Employee a left join Employee b on a.ManagerId=b.Id
-where a.Salary > b.Salary and a.ManagerId is not null
\ No newline at end of file
diff --git a/src.save/main/java/g0101_0200/s0182_duplicate_emails/script.sql b/src.save/main/java/g0101_0200/s0182_duplicate_emails/script.sql
deleted file mode 100644
index 48843b9ab..000000000
--- a/src.save/main/java/g0101_0200/s0182_duplicate_emails/script.sql
+++ /dev/null
@@ -1,3 +0,0 @@
-# Write your MySQL query statement below
-# #Easy #Database #2022_03_04_Time_345_ms_(59.47%)_Space_0B_(100.00%)
-SELECT Email FROM Person GROUP BY Email HAVING COUNT(Email) > 1;
\ No newline at end of file
diff --git a/src.save/main/java/g0101_0200/s0183_customers_who_never_order/script.sql b/src.save/main/java/g0101_0200/s0183_customers_who_never_order/script.sql
deleted file mode 100644
index 2341bca02..000000000
--- a/src.save/main/java/g0101_0200/s0183_customers_who_never_order/script.sql
+++ /dev/null
@@ -1,7 +0,0 @@
-# Write your MySQL query statement below
-# #Easy #Database #2022_03_04_Time_581_ms_(23.03%)_Space_0B_(100.00%)
-SELECT c.Name as Customers
-FROM Customers as c
-LEFT JOIN Orders as o
-ON c.Id = o.CustomerId
-WHERE o.CustomerId is null
\ No newline at end of file
diff --git a/src.save/main/java/g0101_0200/s0184_department_highest_salary/script.sql b/src.save/main/java/g0101_0200/s0184_department_highest_salary/script.sql
deleted file mode 100644
index e172a5b28..000000000
--- a/src.save/main/java/g0101_0200/s0184_department_highest_salary/script.sql
+++ /dev/null
@@ -1,17 +0,0 @@
-# Write your MySQL query statement below
-# #Medium #Database #2022_03_04_Time_576_ms_(64.14%)_Space_0B_(100.00%)
-SELECT
- d.Name AS Department,
- Sel.Name AS Employee,
- Sel.Salary AS Salary
-FROM
-(
- SELECT
- Name,
- Salary,
- DepartmentId,
- DENSE_RANK() OVER (PARTITION BY DepartmentId ORDER BY Salary DESC) AS dr
- FROM Employee
-) AS Sel
-INNER JOIN Department d ON d.Id = Sel.DepartmentId
-WHERE Sel.dr = 1
\ No newline at end of file
diff --git a/src.save/main/java/g0101_0200/s0185_department_top_three_salaries/script.sql b/src.save/main/java/g0101_0200/s0185_department_top_three_salaries/script.sql
deleted file mode 100644
index e05be5a2f..000000000
--- a/src.save/main/java/g0101_0200/s0185_department_top_three_salaries/script.sql
+++ /dev/null
@@ -1,13 +0,0 @@
-# Write your MySQL query statement below
-# #Hard #Database #2022_03_04_Time_763_ms_(63.69%)_Space_0B_(100.00%)
-SELECT D.name AS Department,
- A.name AS Employee,
- A.salary AS Salary
-FROM
- (SELECT *,
- dense_rank() over(PARTITION BY departmentID
- ORDER BY salary DESC) AS rn
- FROM Employee) A
- INNER JOIN Department D ON A.departmentid = D.id
-WHERE A.rn < 4
-ORDER BY Department, Salary DESC
\ No newline at end of file
diff --git a/src.save/main/java/g0101_0200/s0187_repeated_dna_sequences/Solution.java b/src.save/main/java/g0101_0200/s0187_repeated_dna_sequences/Solution.java
deleted file mode 100644
index e21b82558..000000000
--- a/src.save/main/java/g0101_0200/s0187_repeated_dna_sequences/Solution.java
+++ /dev/null
@@ -1,42 +0,0 @@
-package g0101_0200.s0187_repeated_dna_sequences;
-
-// #Medium #String #Hash_Table #Bit_Manipulation #Sliding_Window #Hash_Function #Rolling_Hash
-// #Data_Structure_II_Day_9_String #2022_03_04_Time_32_ms_(67.58%)_Space_73.2_MB_(6.07%)
-
-import java.util.ArrayList;
-import java.util.Collections;
-import java.util.List;
-
-public class Solution {
- public List findRepeatedDnaSequences(String s) {
- if (s.length() < 10) {
- return Collections.emptyList();
- }
- boolean[] seen = new boolean[1024 * 1024];
- boolean[] added = new boolean[1024 * 1024];
- char[] chars = s.toCharArray();
- int buf = 0;
- int[] map = new int[128];
- map['A'] = 0;
- map['C'] = 1;
- map['G'] = 2;
- map['T'] = 3;
- List ans = new ArrayList<>(s.length() / 2);
- for (int i = 0; i < 10; i++) {
- buf = (buf << 2) + map[chars[i]];
- }
- seen[buf] = true;
- for (int i = 10; i < chars.length; i++) {
- buf = ((buf << 2) & 0xFFFFF) + map[chars[i]];
- if (seen[buf]) {
- if (!added[buf]) {
- ans.add(new String(chars, i - 9, 10));
- added[buf] = true;
- }
- } else {
- seen[buf] = true;
- }
- }
- return ans;
- }
-}
diff --git a/src.save/main/java/g0101_0200/s0188_best_time_to_buy_and_sell_stock_iv/Solution.java b/src.save/main/java/g0101_0200/s0188_best_time_to_buy_and_sell_stock_iv/Solution.java
deleted file mode 100644
index d0c8a54de..000000000
--- a/src.save/main/java/g0101_0200/s0188_best_time_to_buy_and_sell_stock_iv/Solution.java
+++ /dev/null
@@ -1,22 +0,0 @@
-package g0101_0200.s0188_best_time_to_buy_and_sell_stock_iv;
-
-// #Hard #Array #Dynamic_Programming #2022_03_04_Time_2_ms_(92.32%)_Space_40.7_MB_(69.51%)
-
-public class Solution {
- public int maxProfit(int k, int[] prices) {
- int n = prices.length;
- int[] dp = new int[k + 1];
- int[] maxdp = new int[k + 1];
- for (int i = 0; i <= k; i++) {
- maxdp[i] = Integer.MIN_VALUE;
- }
- for (int i = 1; i <= n; i++) {
- maxdp[0] = Math.max(maxdp[0], dp[0] - prices[i - 1]);
- for (int j = k; j >= 1; j--) {
- maxdp[j] = Math.max(maxdp[j], dp[j] - prices[i - 1]);
- dp[j] = Math.max(maxdp[j - 1] + prices[i - 1], dp[j]);
- }
- }
- return dp[k];
- }
-}
diff --git a/src.save/main/java/g0101_0200/s0189_rotate_array/Solution.java b/src.save/main/java/g0101_0200/s0189_rotate_array/Solution.java
deleted file mode 100644
index 02d0e5765..000000000
--- a/src.save/main/java/g0101_0200/s0189_rotate_array/Solution.java
+++ /dev/null
@@ -1,24 +0,0 @@
-package g0101_0200.s0189_rotate_array;
-
-// #Medium #Top_100_Liked_Questions #Top_Interview_Questions #Array #Math #Two_Pointers
-// #Algorithm_I_Day_2_Two_Pointers #2022_03_04_Time_1_ms_(83.21%)_Space_64.2_MB_(43.99%)
-
-public class Solution {
- private void reverse(int[] nums, int l, int r) {
- while (l <= r) {
- int temp = nums[l];
- nums[l] = nums[r];
- nums[r] = temp;
- l++;
- r--;
- }
- }
-
- public void rotate(int[] nums, int k) {
- int n = nums.length;
- int t = n - (k % n);
- reverse(nums, 0, t - 1);
- reverse(nums, t, n - 1);
- reverse(nums, 0, n - 1);
- }
-}
diff --git a/src.save/main/java/g0101_0200/s0190_reverse_bits/Solution.java b/src.save/main/java/g0101_0200/s0190_reverse_bits/Solution.java
deleted file mode 100644
index 3244bdcf3..000000000
--- a/src.save/main/java/g0101_0200/s0190_reverse_bits/Solution.java
+++ /dev/null
@@ -1,21 +0,0 @@
-package g0101_0200.s0190_reverse_bits;
-
-// #Easy #Top_Interview_Questions #Bit_Manipulation #Divide_and_Conquer
-// #Algorithm_I_Day_14_Bit_Manipulation #2022_03_04_Time_1_ms_(89.07%)_Space_42.1_MB_(38.84%)
-
-public class Solution {
- // you need treat n as an unsigned value
- public int reverseBits(int n) {
- int ret = 0;
- // because there are 32 bits in total
- for (int i = 0; i < 32; i++) {
- ret = ret << 1;
- // If the bit is 1 we OR it with 1, ie add 1
- if ((n & 1) > 0) {
- ret = ret | 1;
- }
- n = n >>> 1;
- }
- return ret;
- }
-}
diff --git a/src.save/main/java/g0101_0200/s0191_number_of_1_bits/Solution.java b/src.save/main/java/g0101_0200/s0191_number_of_1_bits/Solution.java
deleted file mode 100644
index 181b43322..000000000
--- a/src.save/main/java/g0101_0200/s0191_number_of_1_bits/Solution.java
+++ /dev/null
@@ -1,21 +0,0 @@
-package g0101_0200.s0191_number_of_1_bits;
-
-// #Easy #Top_Interview_Questions #Bit_Manipulation #Algorithm_I_Day_13_Bit_Manipulation
-// #Programming_Skills_I_Day_2_Operator #2022_03_04_Time_0_ms_(100.00%)_Space_39_MB_(58.07%)
-
-public class Solution {
- public int hammingWeight(int n) {
- int sum = 0;
- boolean flag = false;
- if (n < 0) {
- flag = true;
- n = n - Integer.MIN_VALUE;
- }
- while (n > 0) {
- int k = n % 2;
- sum += k;
- n /= 2;
- }
- return flag ? sum + 1 : sum;
- }
-}
diff --git a/src.save/main/java/g0101_0200/s0192_word_frequency/script.sh b/src.save/main/java/g0101_0200/s0192_word_frequency/script.sh
deleted file mode 100644
index 6cf34f5e2..000000000
--- a/src.save/main/java/g0101_0200/s0192_word_frequency/script.sh
+++ /dev/null
@@ -1,3 +0,0 @@
-# Read from the file words.txt and output the word frequency list to stdout.
-# #Medium #Shell #2022_03_04_Time_152_ms_(38.56%)_Space_3.8_MB_(85.55%)
-sed -e 's/ /\n/g' words.txt | sed -e '/^$/d' | sort | uniq -c | sort -r | awk '{print $2" "$1}'
\ No newline at end of file
diff --git a/src.save/main/java/g0101_0200/s0193_valid_phone_numbers/script.sh b/src.save/main/java/g0101_0200/s0193_valid_phone_numbers/script.sh
deleted file mode 100644
index 75aa92d4b..000000000
--- a/src.save/main/java/g0101_0200/s0193_valid_phone_numbers/script.sh
+++ /dev/null
@@ -1,3 +0,0 @@
-# Read from the file file.txt and output all valid phone numbers to stdout.
-# #Easy #Shell #2022_03_04_Time_129_ms_(42.86%)_Space_3.2_MB_(53.31%)
-egrep '^[0-9]{3}-[0-9]{3}-[0-9]{4}$|^\([0-9]{3}\)\s[0-9]{3}-[0-9]{4}$' file.txt
\ No newline at end of file
diff --git a/src.save/main/java/g0101_0200/s0194_transpose_file/script.sh b/src.save/main/java/g0101_0200/s0194_transpose_file/script.sh
deleted file mode 100644
index 472950cbd..000000000
--- a/src.save/main/java/g0101_0200/s0194_transpose_file/script.sh
+++ /dev/null
@@ -1,8 +0,0 @@
-# Read from the file file.txt and print its transposed content to stdout.
-# #Medium #Shell #2022_03_04_Time_0_ms_(100.00%)_Space_3.9_MB_(32.21%)
-wordcount=$(head -1 file.txt | wc -w)
-col_n=1
-while [[ $col_n -le $wordcount ]]; do
- awk "{ print \$$col_n }" file.txt | paste -sd " "
- col_n=$((col_n + 1))
-done
\ No newline at end of file
diff --git a/src.save/main/java/g0101_0200/s0195_tenth_line/script.sh b/src.save/main/java/g0101_0200/s0195_tenth_line/script.sh
deleted file mode 100644
index d86550e74..000000000
--- a/src.save/main/java/g0101_0200/s0195_tenth_line/script.sh
+++ /dev/null
@@ -1,3 +0,0 @@
-# Read from the file file.txt and output the tenth line to stdout.
-# #Easy #Shell #2022_03_04_Time_4_ms_(93.33%)_Space_3.6_MB_(31.23%)
-sed -n 10p file.txt
\ No newline at end of file
diff --git a/src.save/main/java/g0101_0200/s0196_delete_duplicate_emails/script.sql b/src.save/main/java/g0101_0200/s0196_delete_duplicate_emails/script.sql
deleted file mode 100644
index b2c44ef7f..000000000
--- a/src.save/main/java/g0101_0200/s0196_delete_duplicate_emails/script.sql
+++ /dev/null
@@ -1,4 +0,0 @@
-# Write your MySQL query statement below
-# #Easy #Database #2022_03_04_Time_541_ms_(81.09%)_Space_0B_(100.00%)
-DELETE FROM Person
-WHERE Id NOT IN (SELECT id FROM (SELECT Email, MIN(Id) AS 'id' FROM Person GROUP BY Email) t)
\ No newline at end of file
diff --git a/src.save/main/java/g0101_0200/s0197_rising_temperature/script.sql b/src.save/main/java/g0101_0200/s0197_rising_temperature/script.sql
deleted file mode 100644
index 8bc8e1769..000000000
--- a/src.save/main/java/g0101_0200/s0197_rising_temperature/script.sql
+++ /dev/null
@@ -1,6 +0,0 @@
-# Write your MySQL query statement below
-# #Easy #Database #2022_03_04_Time_401_ms_(79.45%)_Space_0B_(100.00%)
-SELECT SecondDate.id as Id
-FROM Weather SecondDate JOIN Weather FirstDate
-ON ADDDATE(FirstDate.recordDate,1) = SecondDate.recordDate
-AND SecondDate.temperature > FirstDate.temperature;
\ No newline at end of file
diff --git a/src.save/main/java/g0101_0200/s0198_house_robber/Solution.java b/src.save/main/java/g0101_0200/s0198_house_robber/Solution.java
deleted file mode 100644
index b5c4fb06a..000000000
--- a/src.save/main/java/g0101_0200/s0198_house_robber/Solution.java
+++ /dev/null
@@ -1,26 +0,0 @@
-package g0101_0200.s0198_house_robber;
-
-// #Medium #Top_100_Liked_Questions #Top_Interview_Questions #Array #Dynamic_Programming
-// #Algorithm_I_Day_12_Dynamic_Programming #Dynamic_Programming_I_Day_3
-// #2022_03_04_Time_0_ms_(100.00%)_Space_42_MB_(11.54%)
-
-public class Solution {
- public int rob(int[] nums) {
- if (nums.length == 0) {
- return 0;
- }
- if (nums.length == 1) {
- return nums[0];
- }
- if (nums.length == 2) {
- return Math.max(nums[0], nums[1]);
- }
- int[] profit = new int[nums.length];
- profit[0] = nums[0];
- profit[1] = Math.max(nums[1], nums[0]);
- for (int i = 2; i < nums.length; i++) {
- profit[i] = Math.max(profit[i - 1], nums[i] + profit[i - 2]);
- }
- return profit[nums.length - 1];
- }
-}
diff --git a/src.save/main/java/g0101_0200/s0199_binary_tree_right_side_view/Solution.java b/src.save/main/java/g0101_0200/s0199_binary_tree_right_side_view/Solution.java
deleted file mode 100644
index 620833f83..000000000
--- a/src.save/main/java/g0101_0200/s0199_binary_tree_right_side_view/Solution.java
+++ /dev/null
@@ -1,41 +0,0 @@
-package g0101_0200.s0199_binary_tree_right_side_view;
-
-// #Medium #Depth_First_Search #Breadth_First_Search #Tree #Binary_Tree
-// #Data_Structure_II_Day_16_Tree #2022_03_04_Time_1_ms_(92.96%)_Space_43.2_MB_(6.01%)
-
-import com_github_leetcode.TreeNode;
-import java.util.ArrayList;
-import java.util.List;
-
-/*
- * Definition for a binary tree node.
- * public class TreeNode {
- * int val;
- * TreeNode left;
- * TreeNode right;
- * TreeNode() {}
- * TreeNode(int val) { this.val = val; }
- * TreeNode(int val, TreeNode left, TreeNode right) {
- * this.val = val;
- * this.left = left;
- * this.right = right;
- * }
- * }
- */
-public class Solution {
- public List rightSideView(TreeNode root) {
- List list = new ArrayList<>();
- recurse(root, 0, list);
- return list;
- }
-
- private void recurse(TreeNode node, int level, List list) {
- if (node != null) {
- if (list.size() < level + 1) {
- list.add(node.val);
- }
- recurse(node.right, level + 1, list);
- recurse(node.left, level + 1, list);
- }
- }
-}
diff --git a/src.save/main/java/g0101_0200/s0200_number_of_islands/Solution.java b/src.save/main/java/g0101_0200/s0200_number_of_islands/Solution.java
deleted file mode 100644
index a7c1c3edf..000000000
--- a/src.save/main/java/g0101_0200/s0200_number_of_islands/Solution.java
+++ /dev/null
@@ -1,35 +0,0 @@
-package g0101_0200.s0200_number_of_islands;
-
-// #Medium #Top_100_Liked_Questions #Top_Interview_Questions #Array #Depth_First_Search
-// #Breadth_First_Search #Matrix #Union_Find
-// #Algorithm_II_Day_6_Breadth_First_Search_Depth_First_Search
-// #Graph_Theory_I_Day_1_Matrix_Related_Problems
-// #2022_03_04_Time_4_ms_(73.02%)_Space_57.7_MB_(19.10%)
-
-public class Solution {
- public int numIslands(char[][] grid) {
- int islands = 0;
- if (grid != null && grid.length != 0 && grid[0].length != 0) {
- for (int i = 0; i < grid.length; i++) {
- for (int j = 0; j < grid[0].length; j++) {
- if (grid[i][j] == '1') {
- dfs(grid, i, j);
- islands++;
- }
- }
- }
- }
- return islands;
- }
-
- private void dfs(char[][] grid, int x, int y) {
- if (x < 0 || grid.length <= x || y < 0 || grid[0].length <= y || grid[x][y] != '1') {
- return;
- }
- grid[x][y] = 'x';
- dfs(grid, x + 1, y);
- dfs(grid, x - 1, y);
- dfs(grid, x, y + 1);
- dfs(grid, x, y - 1);
- }
-}
diff --git a/src.save/main/java/g0201_0300/s0201_bitwise_and_of_numbers_range/Solution.java b/src.save/main/java/g0201_0300/s0201_bitwise_and_of_numbers_range/Solution.java
deleted file mode 100644
index d75322266..000000000
--- a/src.save/main/java/g0201_0300/s0201_bitwise_and_of_numbers_range/Solution.java
+++ /dev/null
@@ -1,46 +0,0 @@
-package g0201_0300.s0201_bitwise_and_of_numbers_range;
-
-// #Medium #Bit_Manipulation #Algorithm_II_Day_19_Bit_Manipulation
-// #2022_03_04_Time_10_ms_(40.99%)_Space_44.3_MB_(27.69%)
-
-public class Solution {
- private static final int[] MASKS =
- new int[] {
- 0,
- 0x80000000,
- 0xC0000000,
- 0xE0000000,
- 0xF0000000,
- 0xF8000000,
- 0xFC000000,
- 0xFE000000,
- 0xFF000000,
- 0xFF800000,
- 0xFFC00000,
- 0xFFE00000,
- 0xFFF00000,
- 0xFFF80000,
- 0xFFFC0000,
- 0xFFFE0000,
- 0xFFFF0000,
- 0xFFFF8000,
- 0xFFFFC000,
- 0xFFFFE000,
- 0xFFFFF000,
- 0xFFFFF800,
- 0xFFFFFC00,
- 0xFFFFFE00,
- 0xFFFFFF00,
- 0xFFFFFF80,
- 0xFFFFFFC0,
- 0xFFFFFFE0,
- 0xFFFFFFF0,
- 0xFFFFFFF8,
- 0xFFFFFFFC,
- 0xFFFFFFFE
- };
-
- public int rangeBitwiseAnd(int left, int right) {
- return left == right ? left : right & MASKS[Integer.numberOfLeadingZeros(left ^ right)];
- }
-}
diff --git a/src.save/main/java/g0201_0300/s0202_happy_number/Solution.java b/src.save/main/java/g0201_0300/s0202_happy_number/Solution.java
deleted file mode 100644
index fed6eb292..000000000
--- a/src.save/main/java/g0201_0300/s0202_happy_number/Solution.java
+++ /dev/null
@@ -1,31 +0,0 @@
-package g0201_0300.s0202_happy_number;
-
-// #Easy #Top_Interview_Questions #Hash_Table #Math #Two_Pointers #Algorithm_II_Day_21_Others
-// #Programming_Skills_I_Day_4_Loop #2022_03_04_Time_1_ms_(93.34%)_Space_41.4_MB_(26.37%)
-
-public class Solution {
- public boolean isHappy(int n) {
- boolean happy;
- int a = n;
- int rem;
- int sum = 0;
- if (a == 1 || a == 7) {
- happy = true;
- } else if (a > 1 && a < 10) {
- happy = false;
- } else {
- while (a != 0) {
- rem = a % 10;
- sum = sum + (rem * rem);
- a = a / 10;
- }
- if (sum != 1) {
- happy = isHappy(sum);
- } else {
- happy = true;
- }
- }
-
- return happy;
- }
-}
diff --git a/src.save/main/java/g0201_0300/s0203_remove_linked_list_elements/Solution.java b/src.save/main/java/g0201_0300/s0203_remove_linked_list_elements/Solution.java
deleted file mode 100644
index b98a1a80c..000000000
--- a/src.save/main/java/g0201_0300/s0203_remove_linked_list_elements/Solution.java
+++ /dev/null
@@ -1,38 +0,0 @@
-package g0201_0300.s0203_remove_linked_list_elements;
-
-// #Easy #Linked_List #Recursion #Data_Structure_I_Day_7_Linked_List
-// #2022_03_04_Time_1_ms_(90.35%)_Space_49.2_MB_(24.46%)
-
-import com_github_leetcode.ListNode;
-
-/*
- * Definition for singly-linked list.
- * public class ListNode {
- * int val;
- * ListNode next;
- * ListNode() {}
- * ListNode(int val) { this.val = val; }
- * ListNode(int val, ListNode next) { this.val = val; this.next = next; }
- * }
- */
-public class Solution {
- public ListNode removeElements(ListNode head, int val) {
- if (head == null) {
- return null;
- }
- while (head != null && head.val == val) {
- head = head.next;
- }
- ListNode r = head;
- ListNode t = head;
- while (r != null) {
- if (r.val == val) {
- t.next = r.next;
- } else {
- t = r;
- }
- r = r.next;
- }
- return head;
- }
-}
diff --git a/src.save/main/java/g0201_0300/s0204_count_primes/Solution.java b/src.save/main/java/g0201_0300/s0204_count_primes/Solution.java
deleted file mode 100644
index c640e0c8f..000000000
--- a/src.save/main/java/g0201_0300/s0204_count_primes/Solution.java
+++ /dev/null
@@ -1,24 +0,0 @@
-package g0201_0300.s0204_count_primes;
-
-// #Medium #Top_Interview_Questions #Array #Math #Enumeration #Number_Theory
-// #2022_03_04_Time_146_ms_(72.74%)_Space_68.8_MB_(22.63%)
-
-public class Solution {
- public int countPrimes(int n) {
- boolean[] isprime = new boolean[n];
- int count = 0;
- for (int i = 2; i * i <= n; i++) {
- if (!isprime[i]) {
- for (int j = i * 2; j < n; j += i) {
- isprime[j] = true;
- }
- }
- }
- for (int i = 2; i < isprime.length; i++) {
- if (!isprime[i]) {
- count++;
- }
- }
- return count;
- }
-}
diff --git a/src.save/main/java/g0201_0300/s0205_isomorphic_strings/Solution.java b/src.save/main/java/g0201_0300/s0205_isomorphic_strings/Solution.java
deleted file mode 100644
index 0f9e6c48e..000000000
--- a/src.save/main/java/g0201_0300/s0205_isomorphic_strings/Solution.java
+++ /dev/null
@@ -1,37 +0,0 @@
-package g0201_0300.s0205_isomorphic_strings;
-
-// #Easy #String #Hash_Table #2022_03_04_Time_1_ms_(100.00%)_Space_42.2_MB_(50.57%)
-
-public class Solution {
- public boolean isIsomorphic(String s, String t) {
- int[] map = new int[128];
- char[] str = s.toCharArray();
- char[] tar = t.toCharArray();
- int n = str.length;
- for (int i = 0; i < n; i++) {
- if (map[tar[i]] == 0) {
- if (search(map, str[i], tar[i]) != -1) {
- return false;
- }
- map[tar[i]] = str[i];
- } else {
- if (map[tar[i]] != str[i]) {
- return false;
- }
- }
- }
- return true;
- }
-
- private int search(int[] map, int tar, int skip) {
- for (int i = 0; i < 128; i++) {
- if (i == skip) {
- continue;
- }
- if (map[i] != 0 && map[i] == tar) {
- return i;
- }
- }
- return -1;
- }
-}
diff --git a/src.save/main/java/g0201_0300/s0206_reverse_linked_list/Solution.java b/src.save/main/java/g0201_0300/s0206_reverse_linked_list/Solution.java
deleted file mode 100644
index 2176acd13..000000000
--- a/src.save/main/java/g0201_0300/s0206_reverse_linked_list/Solution.java
+++ /dev/null
@@ -1,21 +0,0 @@
-package g0201_0300.s0206_reverse_linked_list;
-
-// #Easy #Top_100_Liked_Questions #Top_Interview_Questions #Linked_List #Recursion
-// #Data_Structure_I_Day_8_Linked_List #Algorithm_I_Day_10_Recursion_Backtracking
-// #2022_03_04_Time_0_ms_(100.00%)_Space_43.6_MB_(5.05%)
-
-import com_github_leetcode.ListNode;
-
-public class Solution {
- public ListNode reverseList(ListNode head) {
- ListNode prev = null;
- ListNode curr = head;
- while (curr != null) {
- ListNode next = curr.next;
- curr.next = prev;
- prev = curr;
- curr = next;
- }
- return prev;
- }
-}
diff --git a/src.save/main/java/g0201_0300/s0207_course_schedule/Solution.java b/src.save/main/java/g0201_0300/s0207_course_schedule/Solution.java
deleted file mode 100644
index c625c93f3..000000000
--- a/src.save/main/java/g0201_0300/s0207_course_schedule/Solution.java
+++ /dev/null
@@ -1,45 +0,0 @@
-package g0201_0300.s0207_course_schedule;
-
-// #Medium #Top_100_Liked_Questions #Top_Interview_Questions #Depth_First_Search
-// #Breadth_First_Search #Graph #Topological_Sort
-// #2022_03_04_Time_2_ms_(99.76%)_Space_42.2_MB_(88.54%)
-
-import java.util.ArrayList;
-
-@SuppressWarnings("unchecked")
-public class Solution {
- private static final int WHITE = 0;
- private static final int GRAY = 1;
- private static final int BLACK = 2;
-
- public boolean canFinish(int numCourses, int[][] prerequisites) {
- ArrayList[] adj = new ArrayList[numCourses];
- for (int i = 0; i < numCourses; i++) {
- adj[i] = new ArrayList<>();
- }
- for (int[] pre : prerequisites) {
- adj[pre[1]].add(pre[0]);
- }
- int[] colors = new int[numCourses];
- for (int i = 0; i < numCourses; i++) {
- if (colors[i] == WHITE && !adj[i].isEmpty() && hasCycle(adj, i, colors)) {
- return false;
- }
- }
- return true;
- }
-
- private boolean hasCycle(ArrayList[] adj, int node, int[] colors) {
- colors[node] = GRAY;
- for (int nei : adj[node]) {
- if (colors[nei] == GRAY) {
- return true;
- }
- if (colors[nei] == WHITE && hasCycle(adj, nei, colors)) {
- return true;
- }
- }
- colors[node] = BLACK;
- return false;
- }
-}
diff --git a/src.save/main/java/g0201_0300/s0209_minimum_size_subarray_sum/Solution.java b/src.save/main/java/g0201_0300/s0209_minimum_size_subarray_sum/Solution.java
deleted file mode 100644
index 3df20d1fc..000000000
--- a/src.save/main/java/g0201_0300/s0209_minimum_size_subarray_sum/Solution.java
+++ /dev/null
@@ -1,34 +0,0 @@
-package g0201_0300.s0209_minimum_size_subarray_sum;
-
-// #Medium #Array #Binary_Search #Prefix_Sum #Sliding_Window #Algorithm_II_Day_5_Sliding_Window
-// #2022_03_04_Time_1_ms_(99.98%)_Space_44.6_MB_(39.93%)
-
-public class Solution {
- public int minSubArrayLen(int target, int[] nums) {
- int i = 0;
- int j = 0;
- int sum = 0;
- int min = Integer.MAX_VALUE;
- while (j < nums.length) {
- sum += nums[j];
- if (sum >= target) {
- while (i <= j) {
- if (sum - nums[i] >= target) {
- sum = sum - nums[i];
- i++;
- } else {
- break;
- }
- }
- if (j - i + 1 < min) {
- min = j - i + 1;
- }
- }
- j++;
- }
- if (min == Integer.MAX_VALUE) {
- return 0;
- }
- return min;
- }
-}
diff --git a/src.save/main/java/g0201_0300/s0210_course_schedule_ii/Solution.java b/src.save/main/java/g0201_0300/s0210_course_schedule_ii/Solution.java
deleted file mode 100644
index 20c7380a5..000000000
--- a/src.save/main/java/g0201_0300/s0210_course_schedule_ii/Solution.java
+++ /dev/null
@@ -1,59 +0,0 @@
-package g0201_0300.s0210_course_schedule_ii;
-
-// #Medium #Top_100_Liked_Questions #Top_Interview_Questions #Depth_First_Search
-// #Breadth_First_Search #Graph #Topological_Sort
-// #2022_03_04_Time_7_ms_(74.90%)_Space_50.1_MB_(23.04%)
-
-import java.util.ArrayList;
-import java.util.HashMap;
-import java.util.List;
-import java.util.Map;
-
-public class Solution {
- public int[] findOrder(int numCourses, int[][] prerequisites) {
- Map> graph = new HashMap<>();
- for (int i = 0; i < numCourses; i++) {
- graph.put(i, new ArrayList<>());
- }
-
- for (int[] classes : prerequisites) {
- graph.get(classes[0]).add(classes[1]);
- }
-
- List output = new ArrayList<>();
- Map visited = new HashMap<>();
- for (int c : graph.keySet()) {
- if (dfs(c, graph, visited, output)) {
- return new int[0];
- }
- }
-
- int[] res = new int[output.size()];
- for (int i = 0; i < output.size(); i++) {
- res[i] = output.get(i);
- }
- return res;
- }
-
- private boolean dfs(
- int course,
- Map> graph,
- Map visited,
- List output) {
- if (visited.containsKey(course)) {
- return visited.get(course);
- }
-
- visited.put(course, true);
-
- for (int c : graph.get(course)) {
- if (dfs(c, graph, visited, output)) {
- return true;
- }
- }
-
- visited.put(course, false);
- output.add(course);
- return false;
- }
-}
diff --git a/src.save/main/java/g0201_0300/s0211_design_add_and_search_words_data_structure/WordDictionary.java b/src.save/main/java/g0201_0300/s0211_design_add_and_search_words_data_structure/WordDictionary.java
deleted file mode 100644
index 189fae606..000000000
--- a/src.save/main/java/g0201_0300/s0211_design_add_and_search_words_data_structure/WordDictionary.java
+++ /dev/null
@@ -1,84 +0,0 @@
-package g0201_0300.s0211_design_add_and_search_words_data_structure;
-
-// #Medium #String #Depth_First_Search #Design #Trie
-// #2022_03_05_Time_403_ms_(18.89%)_Space_103.7_MB_(18.65%)
-
-public class WordDictionary {
-
- private static class Node {
- char value;
- boolean isEnd;
- Node[] childs;
-
- Node(char value) {
- this.value = value;
- this.isEnd = false;
- this.childs = new Node[26];
- }
-
- Node getChild(char ch) {
- return this.childs[ch - 'a'];
- }
-
- boolean isChild(char ch) {
- return getChild(ch) != null;
- }
-
- void addChild(char ch) {
- this.childs[ch - 'a'] = new Node(ch);
- }
- }
- // dummy value
- private Node root = new Node('a');
-
- public WordDictionary() {
- // empty constructor
- }
-
- public void addWord(String word) {
- Node node = root;
- for (int i = 0; i < word.length(); i++) {
- char ch = word.charAt(i);
- if (!node.isChild(ch)) {
- node.addChild(ch);
- }
- node = node.getChild(ch);
- }
- node.isEnd = true;
- }
-
- public boolean search(String word) {
- return dfs(this.root, word, 0);
- }
-
- public boolean dfs(Node root, String word, int index) {
- if (root == null) {
- return false;
- }
- // if reached end of word
- if (index == word.length()) {
- return root.isEnd;
- }
- char ch = word.charAt(index);
- if (ch == '.') {
- for (Node child : root.childs) {
- boolean found = dfs(child, word, index + 1);
- if (found) {
- return true;
- }
- }
- return false;
- }
- if (!root.isChild(ch)) {
- return false;
- }
- return dfs(root.getChild(ch), word, index + 1);
- }
-}
-
-/*
- * Your WordDictionary object will be instantiated and called as such:
- * WordDictionary obj = new WordDictionary();
- * obj.addWord(word);
- * boolean param_2 = obj.search(word);
- */
diff --git a/src.save/main/java/g0201_0300/s0212_word_search_ii/Solution.java b/src.save/main/java/g0201_0300/s0212_word_search_ii/Solution.java
deleted file mode 100644
index d155f6208..000000000
--- a/src.save/main/java/g0201_0300/s0212_word_search_ii/Solution.java
+++ /dev/null
@@ -1,62 +0,0 @@
-package g0201_0300.s0212_word_search_ii;
-
-// #Hard #Top_Interview_Questions #Array #String #Matrix #Backtracking #Trie
-// #2022_03_05_Time_20_ms_(96.11%)_Space_43.7_MB_(50.96%)
-
-import java.util.ArrayList;
-import java.util.Collections;
-import java.util.List;
-
-public class Solution {
- private Tree root;
-
- public List findWords(char[][] board, String[] words) {
- if (board.length < 1 || board[0].length < 1) {
- return Collections.emptyList();
- }
- root = new Tree();
- for (String word : words) {
- Tree.addWord(root, word);
- }
- List collected = new ArrayList<>();
- for (int i = 0; i != board.length; ++i) {
- for (int j = 0; j != board[0].length; ++j) {
- dfs(board, i, j, root, collected);
- }
- }
- return collected;
- }
-
- private void dfs(char[][] board, int i, int j, Tree cur, List collected) {
- char c = board[i][j];
- if (c == '-') {
- return;
- }
- cur = cur.getChild(c);
- if (cur == null) {
- return;
- }
- if (cur.end != null) {
- String s = cur.end;
- collected.add(s);
- cur.end = null;
- if (cur.len() == 0) {
- Tree.deleteWord(root, s);
- }
- }
- board[i][j] = '-';
- if (i > 0) {
- dfs(board, i - 1, j, cur, collected);
- }
- if (i + 1 < board.length) {
- dfs(board, i + 1, j, cur, collected);
- }
- if (j > 0) {
- dfs(board, i, j - 1, cur, collected);
- }
- if (j + 1 < board[0].length) {
- dfs(board, i, j + 1, cur, collected);
- }
- board[i][j] = c;
- }
-}
diff --git a/src.save/main/java/g0201_0300/s0213_house_robber_ii/Solution.java b/src.save/main/java/g0201_0300/s0213_house_robber_ii/Solution.java
deleted file mode 100644
index 5ef278650..000000000
--- a/src.save/main/java/g0201_0300/s0213_house_robber_ii/Solution.java
+++ /dev/null
@@ -1,41 +0,0 @@
-package g0201_0300.s0213_house_robber_ii;
-
-// #Medium #Array #Dynamic_Programming #Algorithm_II_Day_12_Dynamic_Programming
-// #Dynamic_Programming_I_Day_3 #2022_03_05_Time_1_ms_(31.05%)_Space_40.7_MB_(45.44%)
-
-public class Solution {
- public int rob(int[] nums) {
- int n = nums.length;
- if (n == 0) {
- return 0;
- }
- if (n == 1) {
- return nums[0];
- }
- if (n == 2) {
- return Math.max(nums[0], nums[1]);
- }
- if (n == 3) {
- return Math.max(nums[0], Math.max(nums[1], nums[2]));
- }
- int max = Integer.MIN_VALUE;
- int[] inc = new int[n];
- int[] exc = new int[n];
- inc[0] = nums[0];
- exc[0] = 0;
- inc[1] = nums[0];
- exc[1] = nums[1];
- inc[2] = nums[2] + nums[0];
- exc[2] = nums[2];
- for (int i = 3; i < n - 1; i++) {
- inc[i] = Math.max(inc[i - 2], inc[i - 3]) + nums[i];
- exc[i] = Math.max(exc[i - 2], exc[i - 3]) + nums[i];
- }
- inc[n - 1] = inc[n - 2];
- exc[n - 1] = Math.max(exc[n - 3], exc[n - 4]) + nums[n - 1];
- for (int i = 0; i < n; i++) {
- max = Math.max(max, Math.max(inc[i], exc[i]));
- }
- return max;
- }
-}
diff --git a/src.save/main/java/g0201_0300/s0214_shortest_palindrome/Solution.java b/src.save/main/java/g0201_0300/s0214_shortest_palindrome/Solution.java
deleted file mode 100644
index 0bf6bbe97..000000000
--- a/src.save/main/java/g0201_0300/s0214_shortest_palindrome/Solution.java
+++ /dev/null
@@ -1,43 +0,0 @@
-package g0201_0300.s0214_shortest_palindrome;
-
-// #Hard #String #Hash_Function #String_Matching #Rolling_Hash
-// #2022_03_05_Time_3_ms_(94.71%)_Space_43.6_MB_(23.95%)
-
-public class Solution {
- public String shortestPalindrome(String s) {
- int i;
- int x;
- int diff;
- int n = s.length();
- int m = (n << 1) + 1;
- char[] letters = new char[m];
- for (i = 0; i < n; i++) {
- letters[i] = letters[m - 1 - i] = s.charAt(i);
- }
- letters[i] = '#';
- int[] lps = new int[m];
- lps[0] = 0;
- for (i = 1; i < m; i++) {
- x = lps[i - 1];
- while (letters[i] != letters[x]) {
- if (x == 0) {
- x = -1;
- break;
- }
- x = lps[x - 1];
- }
- lps[i] = x + 1;
- }
- diff = n - lps[m - 1];
- if (diff == 0) {
- return s;
- } else {
- StringBuilder builder = new StringBuilder();
- for (i = n - 1; i >= n - diff; i--) {
- builder.append(s.charAt(i));
- }
- builder.append(s);
- return builder.toString();
- }
- }
-}
diff --git a/src.save/main/java/g0201_0300/s0215_kth_largest_element_in_an_array/Solution.java b/src.save/main/java/g0201_0300/s0215_kth_largest_element_in_an_array/Solution.java
deleted file mode 100644
index 955a8bab9..000000000
--- a/src.save/main/java/g0201_0300/s0215_kth_largest_element_in_an_array/Solution.java
+++ /dev/null
@@ -1,15 +0,0 @@
-package g0201_0300.s0215_kth_largest_element_in_an_array;
-
-// #Medium #Top_100_Liked_Questions #Top_Interview_Questions #Array #Sorting #Heap_Priority_Queue
-// #Divide_and_Conquer #Quickselect #Data_Structure_II_Day_20_Heap_Priority_Queue
-// #2022_03_05_Time_2_ms_(93.01%)_Space_41.7_MB_(79.50%)
-
-import java.util.Arrays;
-
-public class Solution {
- public int findKthLargest(int[] nums, int k) {
- int n = nums.length;
- Arrays.sort(nums);
- return nums[n - k];
- }
-}
diff --git a/src.save/main/java/g0201_0300/s0216_combination_sum_iii/Solution.java b/src.save/main/java/g0201_0300/s0216_combination_sum_iii/Solution.java
deleted file mode 100644
index 9f783d326..000000000
--- a/src.save/main/java/g0201_0300/s0216_combination_sum_iii/Solution.java
+++ /dev/null
@@ -1,34 +0,0 @@
-package g0201_0300.s0216_combination_sum_iii;
-
-// #Medium #Array #Backtracking #2022_03_05_Time_1_ms_(78.74%)_Space_41.4_MB_(42.68%)
-
-import java.util.ArrayList;
-import java.util.List;
-
-@SuppressWarnings("java:S5413")
-public class Solution {
- public List> combinationSum3(int k, int n) {
- List> res = new ArrayList<>();
- solve(k, n, new ArrayList<>(), res, 0, 1);
- return res;
- }
-
- private void solve(
- int k, int target, List temp, List> res, int sum, int start) {
- if (sum == target && temp.size() == k) {
- res.add(new ArrayList<>(temp));
- return;
- }
- if (temp.size() >= k) {
- return;
- }
- if (sum > target) {
- return;
- }
- for (int i = start; i <= 9; i++) {
- temp.add(i);
- solve(k, target, temp, res, sum + i, i + 1);
- temp.remove(temp.size() - 1);
- }
- }
-}
diff --git a/src.save/main/java/g0201_0300/s0217_contains_duplicate/Solution.java b/src.save/main/java/g0201_0300/s0217_contains_duplicate/Solution.java
deleted file mode 100644
index fbcc5154e..000000000
--- a/src.save/main/java/g0201_0300/s0217_contains_duplicate/Solution.java
+++ /dev/null
@@ -1,19 +0,0 @@
-package g0201_0300.s0217_contains_duplicate;
-
-// #Easy #Top_Interview_Questions #Array #Hash_Table #Sorting #Data_Structure_I_Day_1_Array
-// #Programming_Skills_I_Day_11_Containers_&_Libraries
-// #2022_03_05_Time_27_ms_(16.94%)_Space_70.7_MB_(39.19%)
-
-import java.util.Arrays;
-
-public class Solution {
- public boolean containsDuplicate(int[] nums) {
- Arrays.sort(nums);
- for (int i = 0; i < nums.length - 1; i++) {
- if (nums[i] == nums[i + 1]) {
- return true;
- }
- }
- return false;
- }
-}
diff --git a/src.save/main/java/g0201_0300/s0218_the_skyline_problem/Solution.java b/src.save/main/java/g0201_0300/s0218_the_skyline_problem/Solution.java
deleted file mode 100644
index ba58c5249..000000000
--- a/src.save/main/java/g0201_0300/s0218_the_skyline_problem/Solution.java
+++ /dev/null
@@ -1,43 +0,0 @@
-package g0201_0300.s0218_the_skyline_problem;
-
-// #Hard #Top_Interview_Questions #Array #Heap_Priority_Queue #Ordered_Set #Divide_and_Conquer
-// #Segment_Tree #Binary_Indexed_Tree #Line_Sweep
-// #2022_03_05_Time_21_ms_(80.36%)_Space_53_MB_(23.13%)
-
-import java.util.ArrayList;
-import java.util.Arrays;
-import java.util.List;
-import java.util.TreeMap;
-
-public class Solution {
- public List> getSkyline(int[][] buildings) {
- List> list = new ArrayList<>();
- List lines = new ArrayList<>();
- for (int[] building : buildings) {
- lines.add(new int[] {building[0], building[2]});
- lines.add(new int[] {building[1], -building[2]});
- }
- lines.sort((a, b) -> a[0] == b[0] ? b[1] - a[1] : a[0] - b[0]);
- TreeMap map = new TreeMap<>();
- map.put(0, 1);
- int prev = 0;
- for (int[] line : lines) {
- if (line[1] > 0) {
- map.put(line[1], map.getOrDefault(line[1], 0) + 1);
- } else {
- int f = map.get(-line[1]);
- if (f == 1) {
- map.remove(-line[1]);
- } else {
- map.put(-line[1], f - 1);
- }
- }
- int curr = map.lastKey();
- if (curr != prev) {
- list.add(Arrays.asList(line[0], curr));
- prev = curr;
- }
- }
- return list;
- }
-}
diff --git a/src.save/main/java/g0201_0300/s0219_contains_duplicate_ii/Solution.java b/src.save/main/java/g0201_0300/s0219_contains_duplicate_ii/Solution.java
deleted file mode 100644
index 8b1a47351..000000000
--- a/src.save/main/java/g0201_0300/s0219_contains_duplicate_ii/Solution.java
+++ /dev/null
@@ -1,20 +0,0 @@
-package g0201_0300.s0219_contains_duplicate_ii;
-
-// #Easy #Array #Hash_Table #Sliding_Window #2022_03_05_Time_44_ms_(42.18%)_Space_90.3_MB_(56.13%)
-
-import java.util.HashMap;
-import java.util.Map;
-
-public class Solution {
- public boolean containsNearbyDuplicate(int[] nums, int k) {
- Map map = new HashMap<>();
- int len = nums.length;
- for (int i = 0; i < len; i++) {
- Integer index = map.put(nums[i], i);
- if (index != null && Math.abs(index - i) <= k) {
- return true;
- }
- }
- return false;
- }
-}
diff --git a/src.save/main/java/g0201_0300/s0220_contains_duplicate_iii/Solution.java b/src.save/main/java/g0201_0300/s0220_contains_duplicate_iii/Solution.java
deleted file mode 100644
index 61f3a3d0a..000000000
--- a/src.save/main/java/g0201_0300/s0220_contains_duplicate_iii/Solution.java
+++ /dev/null
@@ -1,38 +0,0 @@
-package g0201_0300.s0220_contains_duplicate_iii;
-
-// #Medium #Array #Sorting #Sliding_Window #Ordered_Set #Bucket_Sort
-// #2022_03_05_Time_46_ms_(62.24%)_Space_53.6_MB_(36.79%)
-
-import java.util.HashMap;
-import java.util.Map;
-
-public class Solution {
- private long getId(long i, long w) {
- return i < 0 ? (i + 1) / w - 1 : i / w;
- }
-
- public boolean containsNearbyAlmostDuplicate(int[] nums, int k, int t) {
- if (t < 0) {
- return false;
- }
- Map d = new HashMap<>();
- long w = (long) t + 1;
- for (int i = 0; i < nums.length; ++i) {
- long m = getId(nums[i], w);
- if (d.containsKey(m)) {
- return true;
- }
- if (d.containsKey(m - 1) && Math.abs(nums[i] - d.get(m - 1)) < w) {
- return true;
- }
- if (d.containsKey(m + 1) && Math.abs(nums[i] - d.get(m + 1)) < w) {
- return true;
- }
- d.put(m, (long) nums[i]);
- if (i >= k) {
- d.remove(getId(nums[i - k], w));
- }
- }
- return false;
- }
-}
diff --git a/src.save/main/java/g0201_0300/s0221_maximal_square/Solution.java b/src.save/main/java/g0201_0300/s0221_maximal_square/Solution.java
deleted file mode 100644
index 405fe8922..000000000
--- a/src.save/main/java/g0201_0300/s0221_maximal_square/Solution.java
+++ /dev/null
@@ -1,33 +0,0 @@
-package g0201_0300.s0221_maximal_square;
-
-// #Medium #Top_100_Liked_Questions #Array #Dynamic_Programming #Matrix
-// #Dynamic_Programming_I_Day_16 #2022_03_05_Time_6_ms_(80.89%)_Space_59.9_MB_(5.32%)
-
-public class Solution {
- public int maximalSquare(char[][] matrix) {
- int m = matrix.length;
- if (m == 0) {
- return 0;
- }
- int n = matrix[0].length;
- if (n == 0) {
- return 0;
- }
- int[][] dp = new int[m + 1][n + 1];
- int max = 0;
- for (int i = 0; i < m; i++) {
- for (int j = 0; j < n; j++) {
- if (matrix[i][j] == '1') {
- // 1 + minimum from cell above, cell to the left, cell diagonal upper-left
- int next = 1 + Math.min(dp[i][j], Math.min(dp[i + 1][j], dp[i][j + 1]));
- // keep track of the maximum value seen
- if (next > max) {
- max = next;
- }
- dp[i + 1][j + 1] = next;
- }
- }
- }
- return max * max;
- }
-}
diff --git a/src.save/main/java/g0201_0300/s0222_count_complete_tree_nodes/Solution.java b/src.save/main/java/g0201_0300/s0222_count_complete_tree_nodes/Solution.java
deleted file mode 100644
index 23e5efa9f..000000000
--- a/src.save/main/java/g0201_0300/s0222_count_complete_tree_nodes/Solution.java
+++ /dev/null
@@ -1,51 +0,0 @@
-package g0201_0300.s0222_count_complete_tree_nodes;
-
-// #Medium #Depth_First_Search #Tree #Binary_Search #Binary_Tree
-// #2022_03_05_Time_0_ms_(100.00%)_Space_49.5_MB_(41.65%)
-
-import com_github_leetcode.TreeNode;
-
-/*
- * Definition for a binary tree node.
- * public class TreeNode {
- * int val;
- * TreeNode left;
- * TreeNode right;
- * TreeNode() {}
- * TreeNode(int val) { this.val = val; }
- * TreeNode(int val, TreeNode left, TreeNode right) {
- * this.val = val;
- * this.left = left;
- * this.right = right;
- * }
- * }
- */
-public class Solution {
- public int countNodes(TreeNode root) {
- if (root == null) {
- return 0;
- }
- int leftHeight = leftHeight(root);
- int rightHeight = rightHeight(root);
- // case 1: When Height(Left sub-tree) = Height(right sub-tree) 2^h - 1
- if (leftHeight == rightHeight) {
- return (1 << leftHeight) - 1;
- } else {
- return 1 + countNodes(root.left) + countNodes(root.right);
- }
- }
-
- private int leftHeight(TreeNode root) {
- if (root == null) {
- return 0;
- }
- return 1 + leftHeight(root.left);
- }
-
- private int rightHeight(TreeNode root) {
- if (root == null) {
- return 0;
- }
- return 1 + rightHeight(root.right);
- }
-}
diff --git a/src.save/main/java/g0201_0300/s0223_rectangle_area/Solution.java b/src.save/main/java/g0201_0300/s0223_rectangle_area/Solution.java
deleted file mode 100644
index e368294eb..000000000
--- a/src.save/main/java/g0201_0300/s0223_rectangle_area/Solution.java
+++ /dev/null
@@ -1,21 +0,0 @@
-package g0201_0300.s0223_rectangle_area;
-
-// #Medium #Math #Geometry #2022_03_05_Time_2_ms_(99.58%)_Space_41.2_MB_(53.89%)
-
-@SuppressWarnings("java:S107")
-public class Solution {
- public int computeArea(int ax1, int ay1, int ax2, int ay2, int bx1, int by1, int bx2, int by2) {
- long left = Math.max(ax1, bx1);
- long right = Math.min(ax2, bx2);
- long top = Math.min(ay2, by2);
- long bottom = Math.max(ay1, by1);
-
- long area = (right - left) * (top - bottom);
- // if not overlaping, either of these two will be non-posittive
- // if right - left = 0, are will automtically be 0 as well
- if (right - left < 0 || top - bottom < 0) {
- area = 0;
- }
- return (int) ((ax2 - ax1) * (ay2 - ay1) + (bx2 - bx1) * (by2 - by1) - area);
- }
-}
diff --git a/src.save/main/java/g0201_0300/s0224_basic_calculator/Solution.java b/src.save/main/java/g0201_0300/s0224_basic_calculator/Solution.java
deleted file mode 100644
index 52597dc32..000000000
--- a/src.save/main/java/g0201_0300/s0224_basic_calculator/Solution.java
+++ /dev/null
@@ -1,46 +0,0 @@
-package g0201_0300.s0224_basic_calculator;
-
-// #Hard #String #Math #Stack #Recursion #2022_03_05_Time_3_ms_(98.82%)_Space_43.8_MB_(56.30%)
-
-public class Solution {
- private int i = 0;
-
- public int calculate(String s) {
- char[] ca = s.toCharArray();
- return helper(ca);
- }
-
- private int helper(char[] ca) {
- int num = 0;
- int prenum = 0;
- boolean isPlus = true;
- for (; i < ca.length; i++) {
- char c = ca[i];
- if (c != ' ') {
- if (c >= '0' && c <= '9') {
- if (num == 0) {
- num = (c - '0');
- } else {
- num = num * 10 + c - '0';
- }
- } else if (c == '+') {
- prenum += num * (isPlus ? 1 : -1);
- isPlus = true;
- num = 0;
- } else if (c == '-') {
- prenum += num * (isPlus ? 1 : -1);
- num = 0;
- isPlus = false;
- } else if (c == '(') {
- i++;
- prenum += helper(ca) * (isPlus ? 1 : -1);
- isPlus = true;
- num = 0;
- } else if (c == ')') {
- return prenum + num * (isPlus ? 1 : -1);
- }
- }
- }
- return prenum + num * (isPlus ? 1 : -1);
- }
-}
diff --git a/src.save/main/java/g0201_0300/s0226_invert_binary_tree/Solution.java b/src.save/main/java/g0201_0300/s0226_invert_binary_tree/Solution.java
deleted file mode 100644
index 3b5f94f26..000000000
--- a/src.save/main/java/g0201_0300/s0226_invert_binary_tree/Solution.java
+++ /dev/null
@@ -1,33 +0,0 @@
-package g0201_0300.s0226_invert_binary_tree;
-
-// #Easy #Top_100_Liked_Questions #Depth_First_Search #Breadth_First_Search #Tree #Binary_Tree
-// #Data_Structure_I_Day_12_Tree #2022_03_14_Time_0_ms_(100.00%)_Space_39.9_MB_(61.13%)
-
-import com_github_leetcode.TreeNode;
-
-/*
- * Definition for a binary tree node.
- * public class TreeNode {
- * int val;
- * TreeNode left;
- * TreeNode right;
- * TreeNode() {}
- * TreeNode(int val) { this.val = val; }
- * TreeNode(int val, TreeNode left, TreeNode right) {
- * this.val = val;
- * this.left = left;
- * this.right = right;
- * }
- * }
- */
-public class Solution {
- public TreeNode invertTree(TreeNode root) {
- if (root == null) {
- return null;
- }
- TreeNode temp = root.left;
- root.left = invertTree(root.right);
- root.right = invertTree(temp);
- return root;
- }
-}
diff --git a/src.save/main/java/g0201_0300/s0227_basic_calculator_ii/Solution.java b/src.save/main/java/g0201_0300/s0227_basic_calculator_ii/Solution.java
deleted file mode 100644
index a9f48e1f3..000000000
--- a/src.save/main/java/g0201_0300/s0227_basic_calculator_ii/Solution.java
+++ /dev/null
@@ -1,48 +0,0 @@
-package g0201_0300.s0227_basic_calculator_ii;
-
-// #Medium #Top_Interview_Questions #String #Math #Stack
-// #2022_03_14_Time_9_ms_(88.15%)_Space_43.5_MB_(65.58%)
-
-public class Solution {
- public int calculate(String s) {
- int sum = 0;
- int tempSum = 0;
- int num = 0;
- char lastSign = '+';
- for (int i = 0; i < s.length(); i++) {
- char c = s.charAt(i);
- if (Character.isDigit(c)) {
- num = num * 10 + c - '0';
- }
- // i == s.length() - 1 will make sure that after last num is
- // made and there is nothing to read anything from 's', the final computation is done
- if (i == s.length() - 1 || !Character.isDigit(c) && c != ' ') {
- switch (lastSign) {
- case '+':
- sum += tempSum;
- tempSum = num;
- break;
- case '-':
- sum += tempSum;
- tempSum = -num;
- break;
- case '*':
- tempSum *= num;
- break;
- case '/':
- if (num != 0) {
- tempSum /= num;
- }
- break;
- default:
- break;
- }
- lastSign = c;
- num = 0;
- }
- }
- // finally, add tempSum to sum
- sum += tempSum;
- return sum;
- }
-}
diff --git a/src.save/main/java/g0201_0300/s0228_summary_ranges/Solution.java b/src.save/main/java/g0201_0300/s0228_summary_ranges/Solution.java
deleted file mode 100644
index 9a6be6784..000000000
--- a/src.save/main/java/g0201_0300/s0228_summary_ranges/Solution.java
+++ /dev/null
@@ -1,56 +0,0 @@
-package g0201_0300.s0228_summary_ranges;
-
-// #Easy #Array #2022_03_14_Time_0_ms_(100.00%)_Space_42.7_MB_(16.88%)
-
-import java.util.ArrayList;
-import java.util.List;
-
-public class Solution {
- public List summaryRanges(int[] nums) {
- List ranges = new ArrayList<>();
- if (nums.length == 0) {
- return ranges;
- }
- // size of array
- int n = nums.length;
- // start of range
- int a = nums[0];
- // end of range
- int b = a;
- StringBuilder strB = new StringBuilder();
- for (int i = 1; i < n; i++) {
- // we need to make a decision if the next element
- // will expand the range
- // i starts at 1, not 0, because 1 is the next
- // candidate for expanding the range
- if (nums[i] != b + 1) {
- // only when our next element does not expand the range
- // do we add the range a->b to our list of ranges
- strB.append(a);
- if (a != b) {
- strB.append("->").append(b);
- }
- ranges.add(strB.toString());
- // since nums[i] is not accounted for by our range a->b
- // because nums[i] is not b+1, we need to set a and b
- // to this new range start point of bigger than b+1
- // maybe it is b+2? b+3? b+4? all we know is it is not b+1
- a = nums[i];
- b = a;
- // Reset string builder
- strB.setLength(0);
- } else {
- // if the next element expands our range we do so
- b++;
- }
- }
- // the only range that is not accounted for at this point is the last range
- // if our a and b are not equal then we add the range accordingly
- strB.append(a);
- if (a != b) {
- strB.append("->").append(b);
- }
- ranges.add(strB.toString());
- return ranges;
- }
-}
diff --git a/src.save/main/java/g0201_0300/s0229_majority_element_ii/Solution.java b/src.save/main/java/g0201_0300/s0229_majority_element_ii/Solution.java
deleted file mode 100644
index a128fc7a0..000000000
--- a/src.save/main/java/g0201_0300/s0229_majority_element_ii/Solution.java
+++ /dev/null
@@ -1,63 +0,0 @@
-package g0201_0300.s0229_majority_element_ii;
-
-// #Medium #Array #Hash_Table #Sorting #Counting
-// #2022_03_14_Time_2_ms_(91.84%)_Space_49.4_MB_(52.73%)
-
-import java.util.ArrayList;
-import java.util.List;
-
-public class Solution {
- public List majorityElement(int[] nums) {
- List results = new ArrayList<>();
- int len = nums.length;
- int first = 0;
- int second = 1;
- int count1 = 0;
- int count2 = 0;
- // now we have two candidates(any integer can be chosed as),and their votes are
- // zero.
- for (int temp : nums) {
- if (temp == first) {
- count1++;
- } else if (temp == second) {
- count2++;
- } else if (count1 == 0) {
- first = temp;
- count1++;
- } else if (count2 == 0) {
- second = temp;
- count2++;
- } else {
- // otherwise,if one of the vote is zero,that's meaning that
- // we only have or even don't have a candidate.So we set the number to the
- // candidate.
- count1--;
- count2--;
- }
- // where we have two candidates whose votes bigger than zero,
- // but the current number is not one of them.Votes decrease by 1 and
- // the current number complete its "mission" and is skipped at the same time.
- // once the cycle finished,the target is left after all the counteraction,as its
- // count is bigger than n/3.
- }
- count1 = 0;
- count2 = 0;
- for (int temp : nums) {
- // check both of them is bigger than n/3.Becasue we may have only one satisfying
- // the demand.
- if (temp == first) {
- count1++;
- }
- if (temp == second) {
- count2++;
- }
- }
- if (count1 > len / 3) {
- results.add(first);
- }
- if (count2 > len / 3) {
- results.add(second);
- }
- return results;
- }
-}
diff --git a/src.save/main/java/g0201_0300/s0230_kth_smallest_element_in_a_bst/Solution.java b/src.save/main/java/g0201_0300/s0230_kth_smallest_element_in_a_bst/Solution.java
deleted file mode 100644
index 350c9d8d2..000000000
--- a/src.save/main/java/g0201_0300/s0230_kth_smallest_element_in_a_bst/Solution.java
+++ /dev/null
@@ -1,55 +0,0 @@
-package g0201_0300.s0230_kth_smallest_element_in_a_bst;
-
-// #Medium #Top_100_Liked_Questions #Top_Interview_Questions #Depth_First_Search #Tree #Binary_Tree
-// #Binary_Search_Tree #Data_Structure_II_Day_17_Tree
-// #2022_03_14_Time_0_ms_(100.00%)_Space_42.1_MB_(84.70%)
-
-import com_github_leetcode.TreeNode;
-
-/*
- * Definition for a binary tree node.
- * public class TreeNode {
- * int val;
- * TreeNode left;
- * TreeNode right;
- * TreeNode() {}
- * TreeNode(int val) { this.val = val; }
- * TreeNode(int val, TreeNode left, TreeNode right) {
- * this.val = val;
- * this.left = left;
- * this.right = right;
- * }
- * }
- */
-public class Solution {
- private int k;
- private int count = 0;
- private int val;
-
- public int kthSmallest(TreeNode root, int k) {
- this.k = k;
- calculate(root);
- return val;
- }
-
- private void calculate(TreeNode node) {
- if (node.left == null && node.right == null) {
- count++;
- if (count == k) {
- this.val = node.val;
- }
- return;
- }
- if (node.left != null) {
- calculate(node.left);
- }
- count++;
- if (count == k) {
- this.val = node.val;
- return;
- }
- if (node.right != null) {
- calculate(node.right);
- }
- }
-}
diff --git a/src.save/main/java/g0201_0300/s0231_power_of_two/Solution.java b/src.save/main/java/g0201_0300/s0231_power_of_two/Solution.java
deleted file mode 100644
index 82dc7f48c..000000000
--- a/src.save/main/java/g0201_0300/s0231_power_of_two/Solution.java
+++ /dev/null
@@ -1,21 +0,0 @@
-package g0201_0300.s0231_power_of_two;
-
-// #Easy #Math #Bit_Manipulation #Recursion #Algorithm_I_Day_13_Bit_Manipulation
-// #2022_03_14_Time_1_ms_(95.76%)_Space_41.4_MB_(36.37%)
-
-public class Solution {
- public boolean isPowerOfTwo(int n) {
- if (n <= 0) {
- return false;
- }
- while (true) {
- if (n == 1) {
- return true;
- }
- if (n % 2 == 1) {
- return false;
- }
- n /= 2;
- }
- }
-}
diff --git a/src.save/main/java/g0201_0300/s0233_number_of_digit_one/Solution.java b/src.save/main/java/g0201_0300/s0233_number_of_digit_one/Solution.java
deleted file mode 100644
index f224df452..000000000
--- a/src.save/main/java/g0201_0300/s0233_number_of_digit_one/Solution.java
+++ /dev/null
@@ -1,27 +0,0 @@
-package g0201_0300.s0233_number_of_digit_one;
-
-// #Hard #Dynamic_Programming #Math #Recursion
-// #2022_03_14_Time_0_ms_(100.00%)_Space_40.4_MB_(61.06%)
-
-@SuppressWarnings("java:S127")
-public class Solution {
- public int countDigitOne(int n) {
- int ans = 0;
- // count total number of 1s appearing in every digit, starting from the last digit
- for (int k = n, cum = 0, curr10 = 1; k > 0; curr10 *= 10) {
- int rem = k % 10;
- int q = k / 10;
- if (rem == 0) {
- ans += q * curr10;
- } else if (rem == 1) {
- ans += q * curr10 + cum + 1;
- } else {
- ans += (q + 1) * curr10;
- }
- k = q;
- // if loop is at 3rd last digit and n = 54321, cum is now = 321
- cum += rem * curr10;
- }
- return ans;
- }
-}
diff --git a/src.save/main/java/g0201_0300/s0234_palindrome_linked_list/Solution.java b/src.save/main/java/g0201_0300/s0234_palindrome_linked_list/Solution.java
deleted file mode 100644
index 62bb746cc..000000000
--- a/src.save/main/java/g0201_0300/s0234_palindrome_linked_list/Solution.java
+++ /dev/null
@@ -1,41 +0,0 @@
-package g0201_0300.s0234_palindrome_linked_list;
-
-// #Easy #Top_100_Liked_Questions #Top_Interview_Questions #Two_Pointers #Stack #Linked_List
-// #Recursion #2022_03_14_Time_5_ms_(89.76%)_Space_53.3_MB_(92.16%)
-
-import com_github_leetcode.ListNode;
-
-public class Solution {
- public boolean isPalindrome(ListNode head) {
- int len = 0;
- ListNode right = head;
- // Culculate the length
- while (right != null) {
- right = right.next;
- len++;
- }
- // Reverse the right half of the list
- len = len / 2;
- right = head;
- for (int i = 0; i < len; i++) {
- right = right.next;
- }
- ListNode prev = null;
- while (right != null) {
- ListNode next = right.next;
- right.next = prev;
- prev = right;
- right = next;
- }
- // Compare left half and right half
- for (int i = 0; i < len; i++) {
- if (prev != null && head.val == prev.val) {
- head = head.next;
- prev = prev.next;
- } else {
- return false;
- }
- }
- return true;
- }
-}
diff --git a/src.save/main/java/g0201_0300/s0235_lowest_common_ancestor_of_a_binary_search_tree/Solution.java b/src.save/main/java/g0201_0300/s0235_lowest_common_ancestor_of_a_binary_search_tree/Solution.java
deleted file mode 100644
index 0fe31c806..000000000
--- a/src.save/main/java/g0201_0300/s0235_lowest_common_ancestor_of_a_binary_search_tree/Solution.java
+++ /dev/null
@@ -1,30 +0,0 @@
-package g0201_0300.s0235_lowest_common_ancestor_of_a_binary_search_tree;
-
-// #Easy #Depth_First_Search #Tree #Binary_Tree #Binary_Search_Tree #Data_Structure_I_Day_14_Tree
-// #2022_03_14_Time_7_ms_(52.79%)_Space_50_MB_(33.78%)
-
-import com_github_leetcode.TreeNode;
-
-/*
- * Definition for a binary tree node.
- * public class TreeNode {
- * int val;
- * TreeNode left;
- * TreeNode right;
- * TreeNode(int x) { val = x; }
- * }
- */
-public class Solution {
- public TreeNode lowestCommonAncestor(TreeNode root, TreeNode p, TreeNode q) {
- while (true) {
- if (root.val > p.val && root.val > q.val) {
- root = root.left;
- } else if (root.val < p.val && root.val < q.val) {
- root = root.right;
- } else {
- break;
- }
- }
- return root;
- }
-}
diff --git a/src.save/main/java/g0201_0300/s0236_lowest_common_ancestor_of_a_binary_tree/Solution.java b/src.save/main/java/g0201_0300/s0236_lowest_common_ancestor_of_a_binary_tree/Solution.java
deleted file mode 100644
index 521438b0e..000000000
--- a/src.save/main/java/g0201_0300/s0236_lowest_common_ancestor_of_a_binary_tree/Solution.java
+++ /dev/null
@@ -1,35 +0,0 @@
-package g0201_0300.s0236_lowest_common_ancestor_of_a_binary_tree;
-
-// #Medium #Top_100_Liked_Questions #Top_Interview_Questions #Depth_First_Search #Tree #Binary_Tree
-// #Data_Structure_II_Day_18_Tree #2022_03_14_Time_11_ms_(46.61%)_Space_47.5_MB_(27.34%)
-
-import com_github_leetcode.TreeNode;
-
-/*
- * Definition for a binary tree node.
- * public class TreeNode {
- * int val;
- * TreeNode left;
- * TreeNode right;
- * TreeNode(int x) { val = x; }
- * }
- */
-public class Solution {
- public TreeNode lowestCommonAncestor(TreeNode root, TreeNode p, TreeNode q) {
- if (root == null) {
- return null;
- }
- if (root.val == p.val || root.val == q.val) {
- return root;
- }
- TreeNode left = lowestCommonAncestor(root.left, p, q);
- TreeNode right = lowestCommonAncestor(root.right, p, q);
- if (left != null && right != null) {
- return root;
- }
- if (left != null) {
- return left;
- }
- return right;
- }
-}
diff --git a/src.save/main/java/g0201_0300/s0237_delete_node_in_a_linked_list/Solution.java b/src.save/main/java/g0201_0300/s0237_delete_node_in_a_linked_list/Solution.java
deleted file mode 100644
index 3c4ebf0d6..000000000
--- a/src.save/main/java/g0201_0300/s0237_delete_node_in_a_linked_list/Solution.java
+++ /dev/null
@@ -1,25 +0,0 @@
-package g0201_0300.s0237_delete_node_in_a_linked_list;
-
-// #Easy #Top_Interview_Questions #Linked_List
-// #2022_03_14_Time_0_ms_(100.00%)_Space_41.6_MB_(69.06%)
-
-import com_github_leetcode.ListNode;
-
-/*
- * Definition for singly-linked list.
- * public class ListNode {
- * int val;
- * ListNode next;
- * ListNode(int x) { val = x; }
- * }
- */
-public class Solution {
- public void deleteNode(ListNode node) {
- while (node.next.next != null) {
- node.val = node.next.val;
- node = node.next;
- }
- node.val = node.next.val;
- node.next = null;
- }
-}
diff --git a/src.save/main/java/g0201_0300/s0238_product_of_array_except_self/Solution.java b/src.save/main/java/g0201_0300/s0238_product_of_array_except_self/Solution.java
deleted file mode 100644
index 91145e243..000000000
--- a/src.save/main/java/g0201_0300/s0238_product_of_array_except_self/Solution.java
+++ /dev/null
@@ -1,28 +0,0 @@
-package g0201_0300.s0238_product_of_array_except_self;
-
-// #Medium #Top_100_Liked_Questions #Top_Interview_Questions #Array #Prefix_Sum
-// #Data_Structure_II_Day_5_Array #2022_03_14_Time_1_ms_(100.00%)_Space_50_MB_(94.82%)
-
-public class Solution {
- public int[] productExceptSelf(int[] nums) {
- int product = 1;
- int[] ans = new int[nums.length];
- for (int num : nums) {
- product = product * num;
- }
- for (int i = 0; i < nums.length; i++) {
- if (nums[i] != 0) {
- ans[i] = product / nums[i];
- } else {
- int p = 1;
- for (int j = 0; j < nums.length; j++) {
- if (j != i) {
- p = p * nums[j];
- }
- }
- ans[i] = p;
- }
- }
- return ans;
- }
-}
diff --git a/src.save/main/java/g0201_0300/s0239_sliding_window_maximum/Solution.java b/src.save/main/java/g0201_0300/s0239_sliding_window_maximum/Solution.java
deleted file mode 100644
index 4ce5f2d83..000000000
--- a/src.save/main/java/g0201_0300/s0239_sliding_window_maximum/Solution.java
+++ /dev/null
@@ -1,33 +0,0 @@
-package g0201_0300.s0239_sliding_window_maximum;
-
-// #Hard #Top_100_Liked_Questions #Top_Interview_Questions #Array #Heap_Priority_Queue
-// #Sliding_Window #Queue #Monotonic_Queue #2022_03_14_Time_25_ms_(95.01%)_Space_52.5_MB_(98.58%)
-
-import java.util.LinkedList;
-
-public class Solution {
- public int[] maxSlidingWindow(int[] nums, int k) {
- int n = nums.length;
- int[] res = new int[n - k + 1];
- int x = 0;
- LinkedList dq = new LinkedList<>();
- int i = 0;
- int j = 0;
- while (j < nums.length) {
- while (!dq.isEmpty() && dq.peekLast() < nums[j]) {
- dq.pollLast();
- }
- dq.addLast(nums[j]);
- if (j - i + 1 == k) {
- res[x] = dq.peekFirst();
- ++x;
- if (dq.peekFirst() == nums[i]) {
- dq.pollFirst();
- }
- ++i;
- }
- ++j;
- }
- return res;
- }
-}
diff --git a/src.save/main/java/g0201_0300/s0240_search_a_2d_matrix_ii/Solution.java b/src.save/main/java/g0201_0300/s0240_search_a_2d_matrix_ii/Solution.java
deleted file mode 100644
index 537513845..000000000
--- a/src.save/main/java/g0201_0300/s0240_search_a_2d_matrix_ii/Solution.java
+++ /dev/null
@@ -1,22 +0,0 @@
-package g0201_0300.s0240_search_a_2d_matrix_ii;
-
-// #Medium #Top_100_Liked_Questions #Top_Interview_Questions #Array #Binary_Search #Matrix
-// #Divide_and_Conquer #Data_Structure_II_Day_4_Array
-// #2022_03_14_Time_9_ms_(71.40%)_Space_57.3_MB_(49.27%)
-
-public class Solution {
- public boolean searchMatrix(int[][] matrix, int target) {
- int r = 0;
- int c = matrix[0].length - 1;
- while (r < matrix.length && c >= 0) {
- if (matrix[r][c] == target) {
- return true;
- } else if (matrix[r][c] > target) {
- c--;
- } else {
- r++;
- }
- }
- return false;
- }
-}
diff --git a/src.save/main/java/g0201_0300/s0241_different_ways_to_add_parentheses/Solution.java b/src.save/main/java/g0201_0300/s0241_different_ways_to_add_parentheses/Solution.java
deleted file mode 100644
index a1d1c44a2..000000000
--- a/src.save/main/java/g0201_0300/s0241_different_ways_to_add_parentheses/Solution.java
+++ /dev/null
@@ -1,69 +0,0 @@
-package g0201_0300.s0241_different_ways_to_add_parentheses;
-
-// #Medium #String #Dynamic_Programming #Math #Recursion #Memoization
-// #2022_03_14_Time_2_ms_(81.46%)_Space_42.8_MB_(40.67%)
-
-import java.util.ArrayList;
-import java.util.HashMap;
-import java.util.List;
-import java.util.Map;
-
-public class Solution {
- public List diffWaysToCompute(String expression) {
- return diffWaysToCompute(expression, new HashMap<>());
- }
-
- private List diffWaysToCompute(String expression, Map> map) {
- if (map.containsKey(expression)) {
- return map.get(expression);
- }
- List values = new ArrayList<>();
- if (!hasOperator(expression)) {
- // base case
- values.add(Integer.parseInt(expression));
- } else {
- // Recursive case. DFS
- for (int i = 0; i < expression.length(); i++) {
- char symbol = expression.charAt(i);
-
- if (!Character.isDigit(symbol)) {
- List left = diffWaysToCompute(expression.substring(0, i), map);
- List right = diffWaysToCompute(expression.substring(i + 1), map);
- for (Integer l : left) {
- for (Integer r : right) {
- switch (symbol) {
- case '+':
- values.add(l + r);
- break;
- case '-':
- values.add(l - r);
- break;
- case '*':
- values.add(l * r);
- break;
- default:
- break;
- }
- }
- }
- }
- }
- }
- map.put(expression, values);
- return values;
- }
-
- private boolean hasOperator(String expression) {
- for (int i = 0; i < expression.length(); i++) {
- switch (expression.charAt(i)) {
- case '+':
- case '-':
- case '*':
- return true;
- default:
- break;
- }
- }
- return false;
- }
-}
diff --git a/src.save/main/java/g0201_0300/s0242_valid_anagram/Solution.java b/src.save/main/java/g0201_0300/s0242_valid_anagram/Solution.java
deleted file mode 100644
index 4933e3490..000000000
--- a/src.save/main/java/g0201_0300/s0242_valid_anagram/Solution.java
+++ /dev/null
@@ -1,24 +0,0 @@
-package g0201_0300.s0242_valid_anagram;
-
-// #Easy #Top_Interview_Questions #String #Hash_Table #Sorting #Data_Structure_I_Day_6_String
-// #Programming_Skills_I_Day_11_Containers_&_Libraries
-// #2022_03_14_Time_2_ms_(98.88%)_Space_43.7_MB_(46.51%)
-
-public class Solution {
- public boolean isAnagram(String s, String t) {
- if (s.length() != t.length()) {
- return false;
- }
- int[] charFreqMap = new int[26];
- for (char c : s.toCharArray()) {
- charFreqMap[c - 'a']++;
- }
- for (char c : t.toCharArray()) {
- if (charFreqMap[c - 'a'] == 0) {
- return false;
- }
- charFreqMap[c - 'a']--;
- }
- return true;
- }
-}
diff --git a/src.save/main/java/g0201_0300/s0257_binary_tree_paths/Solution.java b/src.save/main/java/g0201_0300/s0257_binary_tree_paths/Solution.java
deleted file mode 100644
index b820f65bf..000000000
--- a/src.save/main/java/g0201_0300/s0257_binary_tree_paths/Solution.java
+++ /dev/null
@@ -1,60 +0,0 @@
-package g0201_0300.s0257_binary_tree_paths;
-
-// #Easy #String #Depth_First_Search #Tree #Binary_Tree
-// #2022_03_14_Time_2_ms_(91.59%)_Space_43.2_MB_(39.17%)
-
-import com_github_leetcode.TreeNode;
-import java.util.ArrayList;
-import java.util.List;
-
-/*
- * Definition for a binary tree node.
- * public class TreeNode {
- * int val;
- * TreeNode left;
- * TreeNode right;
- * TreeNode() {}
- * TreeNode(int val) { this.val = val; }
- * TreeNode(int val, TreeNode left, TreeNode right) {
- * this.val = val;
- * this.left = left;
- * this.right = right;
- * }
- * }
- */
-public class Solution {
- private List result;
- private StringBuilder sb;
-
- public List binaryTreePaths(TreeNode root) {
- result = new ArrayList<>();
- if (root == null) {
- return result;
- }
- sb = new StringBuilder();
- walkThrough(root);
- return result;
- }
-
- private void walkThrough(TreeNode root) {
- assert root != null;
- int length = sb.length();
- sb.append(root.val);
- length = sb.length() - length;
- if (root.left == null && root.right == null) {
- // leaf node.
- result.add(sb.toString());
- sb.delete(sb.length() - length, sb.length());
- return;
- }
- sb.append("->");
- length += 2;
- if (root.left != null) {
- walkThrough(root.left);
- }
- if (root.right != null) {
- walkThrough(root.right);
- }
- sb.delete(sb.length() - length, sb.length());
- }
-}
diff --git a/src.save/main/java/g0201_0300/s0258_add_digits/Solution.java b/src.save/main/java/g0201_0300/s0258_add_digits/Solution.java
deleted file mode 100644
index b5da16afa..000000000
--- a/src.save/main/java/g0201_0300/s0258_add_digits/Solution.java
+++ /dev/null
@@ -1,15 +0,0 @@
-package g0201_0300.s0258_add_digits;
-
-// #Easy #Math #Simulation #Number_Theory #2022_03_14_Time_1_ms_(95.33%)_Space_41.9_MB_(13.57%)
-
-public class Solution {
- public int addDigits(int num) {
- if (num == 0) {
- return 0;
- }
- if (num % 9 == 0) {
- return 9;
- }
- return num % 9;
- }
-}
diff --git a/src.save/main/java/g0201_0300/s0260_single_number_iii/Solution.java b/src.save/main/java/g0201_0300/s0260_single_number_iii/Solution.java
deleted file mode 100644
index 53a559f80..000000000
--- a/src.save/main/java/g0201_0300/s0260_single_number_iii/Solution.java
+++ /dev/null
@@ -1,23 +0,0 @@
-package g0201_0300.s0260_single_number_iii;
-
-// #Medium #Array #Bit_Manipulation #2022_03_14_Time_1_ms_(98.18%)_Space_45.4_MB_(27.48%)
-
-public class Solution {
- public int[] singleNumber(int[] nums) {
- int xorSum = 0;
- for (int num : nums) {
- // will give xor of required nos
- xorSum ^= num;
- }
- // find rightmost bit which is set
- int rightBit = xorSum & -xorSum;
- int a = 0;
- for (int num : nums) {
- // xor only those number whose rightmost bit is set
- if ((num & rightBit) != 0) {
- a ^= num;
- }
- }
- return new int[] {a, a ^ xorSum};
- }
-}
diff --git a/src.save/main/java/g0201_0300/s0262_trips_and_users/script.sql b/src.save/main/java/g0201_0300/s0262_trips_and_users/script.sql
deleted file mode 100644
index 13e65168f..000000000
--- a/src.save/main/java/g0201_0300/s0262_trips_and_users/script.sql
+++ /dev/null
@@ -1,14 +0,0 @@
-īģŋ# Write your MySQL query statement below
-# #Hard #Database #2022_03_14_Time_449_ms_(79.92%)_Space_0B_(100.00%)
-SELECT request_at AS "Day",
- ROUND(SUM(CASE
- WHEN t.status!= 'completed' THEN 1
- ELSE 0
- END)/count(*), 2) AS "Cancellation Rate"
-FROM Trips t
-INNER JOIN Users a ON (a.users_id = t.client_id)
-AND (a.banned="No")
-INNER JOIN Users b ON (b.users_id = t.driver_id)
-AND (b.banned="No")
-WHERE request_at BETWEEN "2013-10-01" AND "2013-10-03"
-GROUP BY request_at;
\ No newline at end of file
diff --git a/src.save/main/java/g0201_0300/s0263_ugly_number/Solution.java b/src.save/main/java/g0201_0300/s0263_ugly_number/Solution.java
deleted file mode 100644
index d6446dab6..000000000
--- a/src.save/main/java/g0201_0300/s0263_ugly_number/Solution.java
+++ /dev/null
@@ -1,20 +0,0 @@
-package g0201_0300.s0263_ugly_number;
-
-// #Easy #Math #2022_03_14_Time_1_ms_(95.93%)_Space_41.7_MB_(19.40%)
-
-public class Solution {
- public boolean isUgly(int n) {
- if (n == 1) {
- return true;
- } else if (n <= 0) {
- return false;
- }
- int[] factors = new int[] {2, 3, 5};
- for (int factor : factors) {
- while (n > 1 && n % factor == 0) {
- n /= factor;
- }
- }
- return n == 1;
- }
-}
diff --git a/src.save/main/java/g0201_0300/s0264_ugly_number_ii/Solution.java b/src.save/main/java/g0201_0300/s0264_ugly_number_ii/Solution.java
deleted file mode 100644
index 6597eaf2d..000000000
--- a/src.save/main/java/g0201_0300/s0264_ugly_number_ii/Solution.java
+++ /dev/null
@@ -1,35 +0,0 @@
-package g0201_0300.s0264_ugly_number_ii;
-
-// #Medium #Hash_Table #Dynamic_Programming #Math #Heap_Priority_Queue #Dynamic_Programming_I_Day_11
-// #2022_03_14_Time_3_ms_(88.43%)_Space_42.8_MB_(37.28%)
-
-public class Solution {
- public int nthUglyNumber(int n) {
- int[] ugly = new int[n];
- int i2 = 0;
- int i3 = 0;
- int i5 = 0;
- int ugly2 = 2;
- int ugly3 = 3;
- int ugly5 = 5;
- int nextugly;
- ugly[0] = 1;
- for (int i = 1; i < n; i++) {
- nextugly = Math.min(Math.min(ugly2, ugly3), ugly5);
- ugly[i] = nextugly;
- if (nextugly == ugly2) {
- i2++;
- ugly2 = ugly[i2] * 2;
- }
- if (nextugly == ugly3) {
- i3++;
- ugly3 = ugly[i3] * 3;
- }
- if (nextugly == ugly5) {
- i5++;
- ugly5 = ugly[i5] * 5;
- }
- }
- return ugly[n - 1];
- }
-}
diff --git a/src.save/main/java/g0201_0300/s0268_missing_number/Solution.java b/src.save/main/java/g0201_0300/s0268_missing_number/Solution.java
deleted file mode 100644
index 757aea176..000000000
--- a/src.save/main/java/g0201_0300/s0268_missing_number/Solution.java
+++ /dev/null
@@ -1,15 +0,0 @@
-package g0201_0300.s0268_missing_number;
-
-// #Easy #Top_Interview_Questions #Array #Hash_Table #Math #Sorting #Bit_Manipulation
-// #2022_03_14_Time_0_ms_(100.00%)_Space_51.1_MB_(42.73%)
-
-public class Solution {
- public int missingNumber(int[] nums) {
- int a = nums.length;
- for (int i = 0; i < nums.length; i++) {
- a ^= i;
- a ^= nums[i];
- }
- return a;
- }
-}
diff --git a/src.save/main/java/g0201_0300/s0273_integer_to_english_words/Solution.java b/src.save/main/java/g0201_0300/s0273_integer_to_english_words/Solution.java
deleted file mode 100644
index c8afc4196..000000000
--- a/src.save/main/java/g0201_0300/s0273_integer_to_english_words/Solution.java
+++ /dev/null
@@ -1,62 +0,0 @@
-package g0201_0300.s0273_integer_to_english_words;
-
-// #Hard #String #Math #Recursion #2022_03_14_Time_5_ms_(83.37%)_Space_42.1_MB_(60.23%)
-
-import java.util.StringJoiner;
-
-public class Solution {
- private String[] ones = {
- "One ", "Two ", "Three ", "Four ", "Five ", "Six ", "Seven ", "Eight ", "Nine "
- };
- private String[] teens = {
- "Ten ",
- "Eleven ",
- "Twelve ",
- "Thirteen ",
- "Fourteen ",
- "Fifteen ",
- "Sixteen ",
- "Seventeen ",
- "Eighteen ",
- "Nineteen "
- };
- private String[] twenties = {
- "Twenty ", "Thirty ", "Forty ", "Fifty ", "Sixty ", "Seventy ", "Eighty ", "Ninety "
- };
-
- public String numberToWords(int num) {
- if (num == 0) {
- return "Zero";
- }
- StringJoiner joiner = new StringJoiner("");
- processThreeDigits(joiner, num / 1_000_000_000, "Billion ");
- processThreeDigits(joiner, num / 1_000_000, "Million ");
- processThreeDigits(joiner, num / 1_000, "Thousand ");
- processThreeDigits(joiner, num, null);
- return joiner.toString().trim();
- }
-
- private void processThreeDigits(StringJoiner joiner, int input, String name) {
- int threeDigit = input % 1000;
- if (threeDigit > 0) {
- if (threeDigit / 100 > 0) {
- joiner.add(ones[threeDigit / 100 - 1]);
- String hundred = "Hundred ";
- joiner.add(hundred);
- }
- if (threeDigit % 100 >= 20) {
- joiner.add(twenties[(threeDigit % 100) / 10 - 2]);
- if (threeDigit % 10 > 0) {
- joiner.add(ones[threeDigit % 10 - 1]);
- }
- } else if (threeDigit % 100 >= 10 && threeDigit % 100 < 20) {
- joiner.add(teens[threeDigit % 10]);
- } else if (threeDigit % 100 > 0 && threeDigit % 100 < 10) {
- joiner.add(ones[threeDigit % 10 - 1]);
- }
- if (name != null) {
- joiner.add(name);
- }
- }
- }
-}
diff --git a/src.save/main/java/g0201_0300/s0274_h_index/Solution.java b/src.save/main/java/g0201_0300/s0274_h_index/Solution.java
deleted file mode 100644
index 65d85f858..000000000
--- a/src.save/main/java/g0201_0300/s0274_h_index/Solution.java
+++ /dev/null
@@ -1,36 +0,0 @@
-package g0201_0300.s0274_h_index;
-
-// #Medium #Array #Sorting #Counting_Sort #2022_03_14_Time_2_ms_(51.85%)_Space_43_MB_(5.41%)
-
-import java.util.Arrays;
-
-public class Solution {
- public int hIndex(int[] citations) {
- // Sort array then traverse from end keep track of counter denoting total elements seen so
- // far
- Arrays.sort(citations);
- int count = 0;
- int hIndex = 0;
- for (int i = citations.length - 1; i >= 0; i--) {
- if (i == citations.length - 1 && count == citations[i]) {
- hIndex = citations[i];
- return hIndex;
- // Ex:- 7 10--> counter =8
- } else if (citations[i] <= count && count < citations[i + 1]) {
- hIndex = count;
- return hIndex;
- // Ex:- 7 9 --> counter 6 (incuding 7 there willbe 7 elements)
- } else if (citations[i] == count + 1) {
- hIndex = count + 1;
- return hIndex;
- } else {
- count++;
- }
- }
- // case when no element is hindex so far
- if (count < citations[0]) {
- hIndex = count;
- }
- return hIndex;
- }
-}
diff --git a/src.save/main/java/g0201_0300/s0275_h_index_ii/Solution.java b/src.save/main/java/g0201_0300/s0275_h_index_ii/Solution.java
deleted file mode 100644
index b6fc63a7f..000000000
--- a/src.save/main/java/g0201_0300/s0275_h_index_ii/Solution.java
+++ /dev/null
@@ -1,36 +0,0 @@
-package g0201_0300.s0275_h_index_ii;
-
-// #Medium #Array #Binary_Search #2022_03_14_Time_0_ms_(100.00%)_Space_52.2_MB_(44.51%)
-
-public class Solution {
- public int hIndex(int[] citations) {
- int lo = 1;
- int hi = 1000;
- int ans = 0;
- while (lo <= hi) {
- int mid = (lo + hi) / 2;
- int p = check(mid, citations);
- if (citations.length - p >= mid) {
- ans = mid;
- lo = mid + 1;
- } else {
- hi = mid - 1;
- }
- }
- return ans;
- }
-
- private int check(int v, int[] arr) {
- int lo = 0;
- int hi = arr.length - 1;
- while (lo <= hi) {
- int mid = (lo + hi) / 2;
- if (arr[mid] < v) {
- lo = mid + 1;
- } else {
- hi = mid - 1;
- }
- }
- return lo;
- }
-}
diff --git a/src.save/main/java/g0201_0300/s0278_first_bad_version/Solution.java b/src.save/main/java/g0201_0300/s0278_first_bad_version/Solution.java
deleted file mode 100644
index 6463d8b6e..000000000
--- a/src.save/main/java/g0201_0300/s0278_first_bad_version/Solution.java
+++ /dev/null
@@ -1,23 +0,0 @@
-package g0201_0300.s0278_first_bad_version;
-
-// #Easy #Binary_Search #Interactive #Algorithm_I_Day_1_Binary_Search
-// #2022_03_14_Time_12_ms_(99.50%)_Space_39_MB_(65.09%)
-
-/* The isBadVersion API is defined in the parent class VersionControl.
-boolean isBadVersion(int version); */
-
-public class Solution extends VersionControl {
- public int firstBadVersion(int n) {
- int start = 1;
- int end = n;
- while (start < end) {
- int mid = start + (end - start) / 2;
- if (isBadVersion(mid)) {
- end = mid;
- } else {
- start = mid + 1;
- }
- }
- return start;
- }
-}
diff --git a/src.save/main/java/g0201_0300/s0278_first_bad_version/VersionControl.java b/src.save/main/java/g0201_0300/s0278_first_bad_version/VersionControl.java
deleted file mode 100644
index 2522d779d..000000000
--- a/src.save/main/java/g0201_0300/s0278_first_bad_version/VersionControl.java
+++ /dev/null
@@ -1,13 +0,0 @@
-package g0201_0300.s0278_first_bad_version;
-
-// #Easy #Binary_Search #Interactive #Algorithm_I_Day_1_Binary_Search
-// #2022_03_14_Time_12_ms_(99.50%)_Space_39_MB_(65.09%)
-
-/* The isBadVersion API is defined in the parent class VersionControl.
-boolean isBadVersion(int version); */
-
-public class VersionControl {
- public boolean isBadVersion(int version) {
- return version % 2 == 0;
- }
-}
diff --git a/src.save/main/java/g0201_0300/s0279_perfect_squares/Solution.java b/src.save/main/java/g0201_0300/s0279_perfect_squares/Solution.java
deleted file mode 100644
index 756325366..000000000
--- a/src.save/main/java/g0201_0300/s0279_perfect_squares/Solution.java
+++ /dev/null
@@ -1,34 +0,0 @@
-package g0201_0300.s0279_perfect_squares;
-
-// #Medium #Top_100_Liked_Questions #Top_Interview_Questions #Dynamic_Programming #Math
-// #Breadth_First_Search #Dynamic_Programming_I_Day_21
-// #2022_03_14_Time_0_ms_(100.00%)_Space_39.4_MB_(93.46%)
-
-public class Solution {
- private boolean validSquare(int n) {
- int root = (int) Math.sqrt(n);
- return root * root == n;
- }
-
- public int numSquares(int n) {
- if (n < 4) {
- return n;
- }
- if (validSquare(n)) {
- return 1;
- }
- while ((n & 3) == 0) {
- n >>= 2;
- }
- if ((n & 7) == 7) {
- return 4;
- }
- int x = (int) Math.sqrt(n);
- for (int i = 1; i <= x; i++) {
- if (validSquare(n - i * i)) {
- return 2;
- }
- }
- return 3;
- }
-}
diff --git a/src.save/main/java/g0201_0300/s0282_expression_add_operators/Solution.java b/src.save/main/java/g0201_0300/s0282_expression_add_operators/Solution.java
deleted file mode 100644
index e06819f5b..000000000
--- a/src.save/main/java/g0201_0300/s0282_expression_add_operators/Solution.java
+++ /dev/null
@@ -1,69 +0,0 @@
-package g0201_0300.s0282_expression_add_operators;
-
-// #Hard #String #Math #Backtracking #2022_03_14_Time_7_ms_(99.73%)_Space_45.3_MB_(71.68%)
-
-import java.util.ArrayList;
-import java.util.List;
-
-@SuppressWarnings("java:S107")
-public class Solution {
- public List addOperators(String num, int target) {
- List res = new ArrayList<>();
- if (num.length() == 0 || Long.valueOf(num) > Integer.MAX_VALUE) {
- return res;
- }
- char[] list = num.toCharArray();
- dfs(res, list, 0, 0, target, new char[2 * list.length - 1], 0, 1, '+', 0);
- return res;
- }
-
- private void dfs(
- List res,
- char[] list,
- int i,
- int j,
- int target,
- char[] arr,
- int val,
- int mul,
- char preOp,
- int join) {
- arr[j++] = list[i];
- int digit = 10 * join + (list[i] - '0');
- int result = val + mul * digit;
- if (preOp == '-') {
- result = val - mul * digit;
- }
- if (i == list.length - 1) {
- if (result == target) {
- StringBuilder sb = new StringBuilder();
- for (int k = 0; k < j; k++) {
- sb.append(arr[k]);
- }
- res.add(sb.toString());
- }
- return;
- }
- if (preOp == '+') {
- arr[j] = '+';
- dfs(res, list, i + 1, j + 1, target, arr, val + mul * digit, 1, '+', 0);
- arr[j] = '-';
- dfs(res, list, i + 1, j + 1, target, arr, val + mul * digit, 1, '-', 0);
- arr[j] = '*';
- dfs(res, list, i + 1, j + 1, target, arr, val, mul * digit, '+', 0);
- if (digit != 0) {
- dfs(res, list, i + 1, j, target, arr, val, mul, '+', digit);
- }
- } else {
- arr[j] = '+';
- dfs(res, list, i + 1, j + 1, target, arr, val - mul * digit, 1, '+', 0);
- arr[j] = '-';
- dfs(res, list, i + 1, j + 1, target, arr, val - mul * digit, 1, '-', 0);
- arr[j] = '*';
- dfs(res, list, i + 1, j + 1, target, arr, val, mul * digit, '-', 0);
- if (digit != 0) {
- dfs(res, list, i + 1, j, target, arr, val, mul, '-', digit);
- }
- }
- }
-}
diff --git a/src.save/main/java/g0201_0300/s0283_move_zeroes/Solution.java b/src.save/main/java/g0201_0300/s0283_move_zeroes/Solution.java
deleted file mode 100644
index cc7029661..000000000
--- a/src.save/main/java/g0201_0300/s0283_move_zeroes/Solution.java
+++ /dev/null
@@ -1,23 +0,0 @@
-package g0201_0300.s0283_move_zeroes;
-
-// #Easy #Top_100_Liked_Questions #Top_Interview_Questions #Array #Two_Pointers
-// #Algorithm_I_Day_3_Two_Pointers #Programming_Skills_I_Day_6_Array
-// #2022_03_14_Time_2_ms_(74.00%)_Space_54.7_MB_(38.66%)
-
-public class Solution {
- public void moveZeroes(int[] nums) {
- int firstZero = 0;
- for (int i = 0; i < nums.length; i++) {
- if (nums[i] != 0) {
- swap(firstZero, i, nums);
- firstZero++;
- }
- }
- }
-
- private void swap(int index1, int index2, int[] numbers) {
- int val2 = numbers[index2];
- numbers[index2] = numbers[index1];
- numbers[index1] = val2;
- }
-}
diff --git a/src.save/main/java/g0201_0300/s0287_find_the_duplicate_number/Solution.java b/src.save/main/java/g0201_0300/s0287_find_the_duplicate_number/Solution.java
deleted file mode 100644
index 825a64922..000000000
--- a/src.save/main/java/g0201_0300/s0287_find_the_duplicate_number/Solution.java
+++ /dev/null
@@ -1,17 +0,0 @@
-package g0201_0300.s0287_find_the_duplicate_number;
-
-// #Medium #Top_100_Liked_Questions #Top_Interview_Questions #Array #Binary_Search #Two_Pointers
-// #Bit_Manipulation #2022_03_14_Time_4_ms_(94.82%)_Space_76.1_MB_(27.41%)
-
-public class Solution {
- public int findDuplicate(int[] nums) {
- int[] arr = new int[nums.length + 1];
- for (int num : nums) {
- arr[num] += 1;
- if (arr[num] == 2) {
- return num;
- }
- }
- return 0;
- }
-}
diff --git a/src.save/main/java/g0201_0300/s0289_game_of_life/Solution.java b/src.save/main/java/g0201_0300/s0289_game_of_life/Solution.java
deleted file mode 100644
index 80183ceef..000000000
--- a/src.save/main/java/g0201_0300/s0289_game_of_life/Solution.java
+++ /dev/null
@@ -1,37 +0,0 @@
-package g0201_0300.s0289_game_of_life;
-
-// #Medium #Top_Interview_Questions #Array #Matrix #Simulation
-// #2022_03_14_Time_0_ms_(100.00%)_Space_43.2_MB_(5.22%)
-
-public class Solution {
- public void gameOfLife(int[][] board) {
- int m = board.length;
- int n = board[0].length;
- for (int i = 0; i < m; i++) {
- for (int j = 0; j < n; j++) {
- int lives = lives(board, i, j, m, n);
- if (board[i][j] == 0 && lives == 3) {
- board[i][j] = 2;
- } else if (board[i][j] == 1 && (lives == 2 || lives == 3)) {
- board[i][j] = 3;
- }
- }
- }
- for (int i = 0; i < m; i++) {
- for (int j = 0; j < n; j++) {
- board[i][j] >>= 1;
- }
- }
- }
-
- private int lives(int[][] board, int i, int j, int m, int n) {
- int lives = 0;
- for (int r = Math.max(0, i - 1); r <= Math.min(m - 1, i + 1); r++) {
- for (int c = Math.max(0, j - 1); c <= Math.min(n - 1, j + 1); c++) {
- lives += board[r][c] & 1;
- }
- }
- lives -= board[i][j] & 1;
- return lives;
- }
-}
diff --git a/src.save/main/java/g0201_0300/s0290_word_pattern/Solution.java b/src.save/main/java/g0201_0300/s0290_word_pattern/Solution.java
deleted file mode 100644
index b616cd1db..000000000
--- a/src.save/main/java/g0201_0300/s0290_word_pattern/Solution.java
+++ /dev/null
@@ -1,30 +0,0 @@
-package g0201_0300.s0290_word_pattern;
-
-// #Easy #String #Hash_Table #Data_Structure_II_Day_7_String
-// #2022_03_14_Time_1_ms_(91.62%)_Space_41.9_MB_(13.47%)
-
-import java.util.HashMap;
-import java.util.Map;
-
-public class Solution {
- public boolean wordPattern(String pattern, String s) {
- Map map = new HashMap<>();
- String[] words = s.split(" ");
- if (words.length != pattern.length()) {
- return false;
- }
- for (int i = 0; i < pattern.length(); i++) {
- if (!map.containsKey(pattern.charAt(i))) {
- if (map.containsValue(words[i])) {
- return false;
- }
- map.put(pattern.charAt(i), words[i]);
- } else {
- if (!words[i].equals(map.get(pattern.charAt(i)))) {
- return false;
- }
- }
- }
- return true;
- }
-}
diff --git a/src.save/main/java/g0201_0300/s0292_nim_game/Solution.java b/src.save/main/java/g0201_0300/s0292_nim_game/Solution.java
deleted file mode 100644
index f5f23ffcd..000000000
--- a/src.save/main/java/g0201_0300/s0292_nim_game/Solution.java
+++ /dev/null
@@ -1,9 +0,0 @@
-package g0201_0300.s0292_nim_game;
-
-// #Easy #Math #Game_Theory #Brainteaser #2022_03_14_Time_0_ms_(100.00%)_Space_41.2_MB_(15.52%)
-
-public class Solution {
- public boolean canWinNim(int n) {
- return n % 4 != 0;
- }
-}
diff --git a/src.save/main/java/g0201_0300/s0297_serialize_and_deserialize_binary_tree/Codec.java b/src.save/main/java/g0201_0300/s0297_serialize_and_deserialize_binary_tree/Codec.java
deleted file mode 100644
index b2ca63681..000000000
--- a/src.save/main/java/g0201_0300/s0297_serialize_and_deserialize_binary_tree/Codec.java
+++ /dev/null
@@ -1,68 +0,0 @@
-package g0201_0300.s0297_serialize_and_deserialize_binary_tree;
-
-// #Hard #Top_100_Liked_Questions #Top_Interview_Questions #String #Depth_First_Search
-// #Breadth_First_Search #Tree #Binary_Tree #Design #Data_Structure_II_Day_18_Tree
-// #2022_03_14_Time_9_ms_(91.82%)_Space_50.6_MB_(65.86%)
-
-import com_github_leetcode.TreeNode;
-
-/*
- * Definition for a binary tree node.
- * public class TreeNode {
- * int val;
- * TreeNode left;
- * TreeNode right;
- * TreeNode(int x) { val = x; }
- * }
- */
-public class Codec {
- private static final int BASE_OFFSET = 1000;
- private static final String DELIM = "*";
- private int offset;
-
- // Encodes a tree to a single string.
- public String serialize(TreeNode root) {
- StringBuilder sb = new StringBuilder();
- offset = 0;
- serialize(root, sb);
- return sb.toString();
- }
-
- public void serialize(TreeNode root, StringBuilder sb) {
- // all nodes fit into 4 bits.
- // IFF we offset at 0. So encode(val) = val + min(default - 1000)
- if (root == null) {
- sb.append(DELIM);
- return;
- }
- String s = Integer.toHexString(root.val + BASE_OFFSET);
- StringBuilder sb2 = new StringBuilder();
- for (int i = 0; i < 3 - s.length(); i++) {
- sb2.append('0');
- }
- sb2.append(s);
- sb.append(sb2);
- serialize(root.left, sb);
- serialize(root.right, sb);
- }
-
- // Decodes your encoded data to tree.
- public TreeNode deserialize(String data) {
- if (data.charAt(offset) == '*') {
- offset++;
- return null;
- }
- TreeNode root =
- new TreeNode(
- Integer.parseInt(data.substring(offset, offset + 3), 16) - BASE_OFFSET);
- offset += 3;
- root.left = deserialize(data);
- root.right = deserialize(data);
- return root;
- }
-}
-
-// Your Codec object will be instantiated and called as such:
-// Codec ser = new Codec();
-// Codec deser = new Codec();
-// TreeNode ans = deser.deserialize(ser.serialize(root));
diff --git a/src.save/main/java/g0201_0300/s0299_bulls_and_cows/Solution.java b/src.save/main/java/g0201_0300/s0299_bulls_and_cows/Solution.java
deleted file mode 100644
index 7cc05a1fd..000000000
--- a/src.save/main/java/g0201_0300/s0299_bulls_and_cows/Solution.java
+++ /dev/null
@@ -1,30 +0,0 @@
-package g0201_0300.s0299_bulls_and_cows;
-
-// #Medium #String #Hash_Table #Counting #2022_03_14_Time_8_ms_(67.24%)_Space_43.3_MB_(22.27%)
-
-public class Solution {
- public String getHint(String secret, String guess) {
- final int[] ans = new int[10];
- int bulls = 0;
- int cows = 0;
- for (int i = 0; i < secret.length(); i++) {
- final int s = Character.getNumericValue(secret.charAt(i));
- final int g = Character.getNumericValue(guess.charAt(i));
- if (s == g) {
- bulls++;
- } else {
- // digit s was already seen in guess, is being seen again in secret
- if (ans[s] < 0) {
- cows++;
- }
- // digit was already seen in secret, now being seen again in guess
- if (ans[g] > 0) {
- cows++;
- }
- ans[s]++;
- ans[g]--;
- }
- }
- return bulls + "A" + cows + "B";
- }
-}
diff --git a/src.save/main/java/g0201_0300/s0300_longest_increasing_subsequence/Solution.java b/src.save/main/java/g0201_0300/s0300_longest_increasing_subsequence/Solution.java
deleted file mode 100644
index 36f1a0958..000000000
--- a/src.save/main/java/g0201_0300/s0300_longest_increasing_subsequence/Solution.java
+++ /dev/null
@@ -1,43 +0,0 @@
-package g0201_0300.s0300_longest_increasing_subsequence;
-
-// #Medium #Top_100_Liked_Questions #Top_Interview_Questions #Array #Dynamic_Programming
-// #Binary_Search #Algorithm_II_Day_16_Dynamic_Programming #Dynamic_Programming_I_Day_18
-// #2022_03_14_Time_3_ms_(96.86%)_Space_44.7_MB_(22.48%)
-
-public class Solution {
- public int lengthOfLIS(int[] nums) {
- if (nums == null || nums.length == 0) {
- return 0;
- }
- int[] dp = new int[nums.length + 1];
- // prefill the dp table
- for (int i = 1; i < dp.length; i++) {
- dp[i] = Integer.MAX_VALUE;
- }
- int left = 1;
- int right = 1;
- for (int curr : nums) {
- int start = left;
- int end = right;
- // binary search, find the one that is lower than curr
- while (start + 1 < end) {
- int mid = start + (end - start) / 2;
- if (dp[mid] > curr) {
- end = mid;
- } else {
- start = mid;
- }
- }
- // update our dp table
- if (dp[start] > curr) {
- dp[start] = curr;
- } else if (curr > dp[start] && curr < dp[end]) {
- dp[end] = curr;
- } else if (curr > dp[end]) {
- dp[++end] = curr;
- right++;
- }
- }
- return right;
- }
-}
diff --git a/src.save/main/java/g0301_0400/s0301_remove_invalid_parentheses/Solution.java b/src.save/main/java/g0301_0400/s0301_remove_invalid_parentheses/Solution.java
deleted file mode 100644
index 89ec6474a..000000000
--- a/src.save/main/java/g0301_0400/s0301_remove_invalid_parentheses/Solution.java
+++ /dev/null
@@ -1,87 +0,0 @@
-package g0301_0400.s0301_remove_invalid_parentheses;
-
-// #Hard #String #Breadth_First_Search #Backtracking
-// #2022_03_14_Time_4_ms_(86.17%)_Space_42.6_MB_(71.40%)
-
-import java.util.ArrayList;
-import java.util.List;
-
-public class Solution {
- public List removeInvalidParentheses(String s) {
- List res = new ArrayList<>();
- // reversed+inverted
- boolean ri = false;
- dfs(s, 0, 0, res, ri);
- return res;
- }
-
- // BASIC IDEA: find prefix w/ extra ")".
- // THEN use for loop to delete ")"s inside prefix, making recursive calls on the ENTIRE STRING
- // b/c you don't know where the next ")" will be deleted.
- private void dfs(String s, int deletionSearch, int stackSearch, List res, boolean ri) {
- // functions imilarly to LC20. Valid Parenthesis, -1 for ")" and +1 for "("
- int stack = 0;
- // see recursive call for explanation
- int p = stackSearch;
- while (p < s.length() && stack >= 0) {
- if (s.charAt(p) == ')') {
- stack--;
- }
- if (s.charAt(p) == '(') {
- stack++;
- }
- p++;
- }
- if (stack < 0) {
- // p already goes beyond the prefix by +1
- String prefix = s.substring(0, p);
- // remove extra ")" from prefix
- for (int i = deletionSearch; i < prefix.length(); i++) {
- // find last ")" in ")))...)" to avoid duplicates
- if (s.charAt(i) == ')' && (i == prefix.length() - 1 || s.charAt(i + 1) != ')')) {
- // remove s.charAt(i) and recurse
- // NOTE: p-1 b/c after you make a deletion, you know that the prefix is valid,
- // so there's no point in recounting ")"
- // NOTE: p-1 is the start index for COUNTING ")" in the recursive call, not for
- // DELETIONS.
- // Think of the DELETION index as SEPARATE from the COUNTING/STACK index.
- dfs(s.substring(0, i) + s.substring(i + 1), deletionSearch, p - 1, res, ri);
- // for next iteration, can only search BEYOND i in recursive calls for the ")"
- // to delete
- deletionSearch = i + 1;
- }
- }
- } else {
- // no extra ")" found
- // repeat for "("
- if (!ri) {
- // reverse + invert
- s = reverseInvert(s);
- // call again
- dfs(s, 0, 0, res, true);
- } else {
- // done with both ")" and "("
- // revert to original arr
- s = reverseInvert(s);
- res.add(s);
- }
- }
- }
-
- // reverses and inverts to accomplish r->l scan
- private String reverseInvert(String s) {
- StringBuilder sb = new StringBuilder();
- // invert
- for (char c : s.toCharArray()) {
- if (c == '(') {
- sb.append(')');
- } else if (c == ')') {
- sb.append('(');
- } else {
- sb.append(c);
- }
- }
- // reverse
- return sb.reverse().toString();
- }
-}
diff --git a/src.save/main/java/g0301_0400/s0303_range_sum_query_immutable/NumArray.java b/src.save/main/java/g0301_0400/s0303_range_sum_query_immutable/NumArray.java
deleted file mode 100644
index 83fcbb21e..000000000
--- a/src.save/main/java/g0301_0400/s0303_range_sum_query_immutable/NumArray.java
+++ /dev/null
@@ -1,26 +0,0 @@
-package g0301_0400.s0303_range_sum_query_immutable;
-
-// #Easy #Array #Design #Prefix_Sum #Programming_Skills_I_Day_12_Class_&_Object
-// #2022_03_14_Time_6_ms_(100.00%)_Space_45_MB_(89.49%)
-
-public class NumArray {
- private int[] sums;
-
- public NumArray(int[] nums) {
- sums = new int[nums.length];
- for (int i = 0; i < nums.length; i++) {
- if (i == 0) {
- sums[i] = nums[i];
- } else {
- sums[i] = sums[i - 1] + nums[i];
- }
- }
- }
-
- public int sumRange(int i, int j) {
- if (i == 0) {
- return sums[j];
- }
- return sums[j] - sums[i - 1];
- }
-}
diff --git a/src.save/main/java/g0301_0400/s0306_additive_number/Solution.java b/src.save/main/java/g0301_0400/s0306_additive_number/Solution.java
deleted file mode 100644
index cafb03471..000000000
--- a/src.save/main/java/g0301_0400/s0306_additive_number/Solution.java
+++ /dev/null
@@ -1,38 +0,0 @@
-package g0301_0400.s0306_additive_number;
-
-// #Medium #String #Backtracking #2022_03_14_Time_1_ms_(87.31%)_Space_41.7_MB_(53.17%)
-
-public class Solution {
- public boolean isAdditiveNumber(String num) {
- int n = num.length();
- for (int i = 1; i <= n / 2; ++i) {
- for (int j = 1; Math.max(j, i) <= n - i - j; ++j) {
- if (isValid(i, j, num)) {
- return true;
- }
- }
- }
- return false;
- }
-
- private boolean isValid(int i, int j, String num) {
- if (num.charAt(0) == '0' && i > 1) {
- return false;
- }
- if (num.charAt(i) == '0' && j > 1) {
- return false;
- }
- String sum;
- Long x1 = Long.parseLong(num.substring(0, i));
- Long x2 = Long.parseLong(num.substring(i, i + j));
- for (int start = i + j; start != num.length(); start += sum.length()) {
- x2 = x2 + x1;
- x1 = x2 - x1;
- sum = x2.toString();
- if (!num.startsWith(sum, start)) {
- return false;
- }
- }
- return true;
- }
-}
diff --git a/src.save/main/java/g0301_0400/s0307_range_sum_query_mutable/NumArray.java b/src.save/main/java/g0301_0400/s0307_range_sum_query_mutable/NumArray.java
deleted file mode 100644
index 01f282f7c..000000000
--- a/src.save/main/java/g0301_0400/s0307_range_sum_query_mutable/NumArray.java
+++ /dev/null
@@ -1,43 +0,0 @@
-package g0301_0400.s0307_range_sum_query_mutable;
-
-// #Medium #Array #Design #Segment_Tree #Binary_Indexed_Tree
-// #2022_03_14_Time_61_ms_(98.40%)_Space_73.8_MB_(80.22%)
-
-public class NumArray {
- private int[] nums;
- private int sum;
-
- public NumArray(int[] nums) {
- this.nums = nums;
- sum = 0;
- for (int num : nums) {
- sum += num;
- }
- }
-
- public void update(int index, int val) {
- sum -= nums[index] - val;
- nums[index] = val;
- }
-
- public int sumRange(int left, int right) {
- int sumRange = 0;
- if ((right - left) < nums.length / 2) {
- // Array to sum is less than half
- for (int i = left; i <= right; i++) {
- sumRange += nums[i];
- }
- } else {
- // Array to sum is more than half
- // Better to take total sum and substract the numbers not in range
- sumRange = sum;
- for (int i = 0; i < left; i++) {
- sumRange -= nums[i];
- }
- for (int i = right + 1; i < nums.length; i++) {
- sumRange -= nums[i];
- }
- }
- return sumRange;
- }
-}
diff --git a/src.save/main/java/g0301_0400/s0309_best_time_to_buy_and_sell_stock_with_cooldown/Solution.java b/src.save/main/java/g0301_0400/s0309_best_time_to_buy_and_sell_stock_with_cooldown/Solution.java
deleted file mode 100644
index 07207d30b..000000000
--- a/src.save/main/java/g0301_0400/s0309_best_time_to_buy_and_sell_stock_with_cooldown/Solution.java
+++ /dev/null
@@ -1,69 +0,0 @@
-package g0301_0400.s0309_best_time_to_buy_and_sell_stock_with_cooldown;
-
-// #Medium #Array #Dynamic_Programming #Dynamic_Programming_I_Day_8
-// #2022_03_14_Time_0_ms_(100.00%)_Space_40.3_MB_(69.21%)
-
-public class Solution {
- /*
- * The series of problems are typical dp. The key for dp is to find the variables to
- * represent the states and deduce the transition function.
- *
- * Of course one may come up with a O(1) space solution directly, but I think it is better
- * to be generous when you think and be greedy when you implement.
- *
- * The natural states for this problem is the 3 possible transactions : buy, sell, rest.
- * Here rest means no transaction on that day (aka cooldown).
- *
- * Then the transaction sequences can end with any of these three states.
- *
- * For each of them we make an array, buy[n], sell[n] and rest[n].
- *
- * buy[i] means before day i what is the maxProfit for any sequence end with buy.
- *
- * sell[i] means before day i what is the maxProfit for any sequence end with sell.
- *
- * rest[i] means before day i what is the maxProfit for any sequence end with rest.
- *
- * Then we want to deduce the transition functions for buy sell and rest. By definition we
- * have:
- *
- * buy[i] = max(rest[i-1]-price, buy[i-1])
- * sell[i] = max(buy[i-1]+price, sell[i-1])
- * rest[i] = max(sell[i-1], buy[i-1], rest[i-1])
- *
- * Where price is the price of day i. All of these are very straightforward. They simply represents :
- *
- * (1) We have to `rest` before we `buy` and
- * (2) we have to `buy` before we `sell`
- * One tricky point is how do you make sure you sell before you buy, since from the equations it seems that
- * [buy, rest, buy] is entirely possible.
- *
- * Well, the answer lies within the fact that buy[i] <= rest[i] which means rest[i] =
- * max(sell[i-1], rest[i-1]). That made sure [buy, rest, buy] is never occurred.
- *
- * A further observation is that and rest[i] <= sell[i] is also true therefore
- *
- * rest[i] = sell[i-1] Substitute this in to buy[i] we now have 2 functions instead of 3:
- *
- * buy[i] = max(sell[i-2]-price, buy[i-1]) sell[i] = max(buy[i-1]+price, sell[i-1]) This is
- * better than 3, but
- *
- * we can do even better
- *
- * Since states of day i relies only on i-1 and i-2 we can reduce the O(n) space to O(1).
- * And here we are at our final solution:
- */
- public int maxProfit(int[] prices) {
- int sell = 0;
- int prevSell = 0;
- int buy = Integer.MIN_VALUE;
- int prevBuy;
- for (int price : prices) {
- prevBuy = buy;
- buy = Math.max(prevSell - price, prevBuy);
- prevSell = sell;
- sell = Math.max(prevBuy + price, prevSell);
- }
- return sell;
- }
-}
diff --git a/src.save/main/java/g0301_0400/s0310_minimum_height_trees/Solution.java b/src.save/main/java/g0301_0400/s0310_minimum_height_trees/Solution.java
deleted file mode 100644
index 24525b279..000000000
--- a/src.save/main/java/g0301_0400/s0310_minimum_height_trees/Solution.java
+++ /dev/null
@@ -1,58 +0,0 @@
-package g0301_0400.s0310_minimum_height_trees;
-
-// #Medium #Depth_First_Search #Breadth_First_Search #Graph #Topological_Sort
-// #2022_03_14_Time_22_ms_(94.43%)_Space_75.7_MB_(51.83%)
-
-import java.util.ArrayList;
-import java.util.LinkedList;
-import java.util.List;
-import java.util.Queue;
-
-@SuppressWarnings("unchecked")
-public class Solution {
- public List findMinHeightTrees(int n, int[][] edges) {
- List answer = new ArrayList<>();
- if (n == 1) {
- answer.add(0);
- return answer;
- }
- List[] graph = new ArrayList[n];
- int[] degree = new int[n];
- for (int i = 0; i < n; i++) {
- graph[i] = new ArrayList<>();
- }
- for (int[] edge : edges) {
- graph[edge[0]].add(edge[1]);
- graph[edge[1]].add(edge[0]);
- degree[edge[0]]++;
- degree[edge[1]]++;
- }
- Queue leaf = new LinkedList<>();
- int remainingNodes = n;
- for (int i = 0; i < n; i++) {
- if (degree[i] == 1) {
- leaf.add(i);
- }
- }
- while (!leaf.isEmpty()) {
- // We found answer if queue left with <=2 elements
- if (remainingNodes <= 2) {
- break;
- }
- int size = leaf.size();
- while (--size >= 0) {
- int l = leaf.poll();
- remainingNodes--;
- for (int adj : graph[l]) {
- // edge is removed so degree will decrease for both vertex
- degree[adj]--;
- if (degree[adj] == 1) {
- leaf.add(adj);
- }
- }
- }
- }
- answer.addAll(leaf);
- return answer;
- }
-}
diff --git a/src.save/main/java/g0301_0400/s0312_burst_balloons/Solution.java b/src.save/main/java/g0301_0400/s0312_burst_balloons/Solution.java
deleted file mode 100644
index bf96cd25e..000000000
--- a/src.save/main/java/g0301_0400/s0312_burst_balloons/Solution.java
+++ /dev/null
@@ -1,31 +0,0 @@
-package g0301_0400.s0312_burst_balloons;
-
-// #Hard #Array #Dynamic_Programming #2022_03_14_Time_53_ms_(86.06%)_Space_43.3_MB_(27.02%)
-
-public class Solution {
- public int maxCoins(int[] nums) {
- if (nums.length == 0) {
- return 0;
- }
- int[][] dp = new int[nums.length][nums.length];
- return balloonBurstDp(nums, dp);
- }
-
- private int balloonBurstDp(int[] nums, int[][] dp) {
- for (int gap = 0; gap < nums.length; gap++) {
- for (int si = 0, ei = gap; ei < nums.length; si++, ei++) {
- int l = (si - 1 == -1) ? 1 : nums[si - 1];
- int r = (ei + 1 == nums.length) ? 1 : nums[ei + 1];
- int maxAns = (int) -1e7;
- for (int cut = si; cut <= ei; cut++) {
- int leftAns = si == cut ? 0 : dp[si][cut - 1];
- int rightAns = ei == cut ? 0 : dp[cut + 1][ei];
- int myAns = leftAns + l * nums[cut] * r + rightAns;
- maxAns = Math.max(maxAns, myAns);
- }
- dp[si][ei] = maxAns;
- }
- }
- return dp[0][nums.length - 1];
- }
-}
diff --git a/src.save/main/java/g0301_0400/s0313_super_ugly_number/Solution.java b/src.save/main/java/g0301_0400/s0313_super_ugly_number/Solution.java
deleted file mode 100644
index 8f8ab3fec..000000000
--- a/src.save/main/java/g0301_0400/s0313_super_ugly_number/Solution.java
+++ /dev/null
@@ -1,32 +0,0 @@
-package g0301_0400.s0313_super_ugly_number;
-
-// #Medium #Array #Hash_Table #Dynamic_Programming #Math #Heap_Priority_Queue
-// #2022_03_14_Time_280_ms_(86.61%)_Space_46.9_MB_(30.44%)
-
-public class Solution {
- public int nthSuperUglyNumber(int n, int[] primes) {
- if (primes.length == 0) {
- return 1;
- }
- int[] uglies = new int[n];
- uglies[0] = 1;
- int[] uglyToMultiplyBy = new int[primes.length];
-
- for (int i = 1; i < n; i++) {
- int min = primes[0] * uglies[uglyToMultiplyBy[0]];
- int minIdx = 0;
- for (int j = 1; j < primes.length; j++) {
- int currNum = primes[j] * uglies[uglyToMultiplyBy[j]];
- if (currNum < min) {
- min = currNum;
- minIdx = j;
- } else if (currNum == min) {
- uglyToMultiplyBy[j]++;
- }
- }
- uglyToMultiplyBy[minIdx]++;
- uglies[i] = min;
- }
- return uglies[n - 1];
- }
-}
diff --git a/src.save/main/java/g0301_0400/s0315_count_of_smaller_numbers_after_self/Solution.java b/src.save/main/java/g0301_0400/s0315_count_of_smaller_numbers_after_self/Solution.java
deleted file mode 100644
index 23fd26d6b..000000000
--- a/src.save/main/java/g0301_0400/s0315_count_of_smaller_numbers_after_self/Solution.java
+++ /dev/null
@@ -1,53 +0,0 @@
-package g0301_0400.s0315_count_of_smaller_numbers_after_self;
-
-// #Hard #Top_Interview_Questions #Array #Binary_Search #Ordered_Set #Divide_and_Conquer
-// #Segment_Tree #Binary_Indexed_Tree #Merge_Sort
-// #2022_03_14_Time_34_ms_(96.38%)_Space_118.8_MB_(72.90%)
-
-import java.util.LinkedList;
-import java.util.List;
-
-public class Solution {
- public List countSmaller(int[] nums) {
- int minVal = 10001;
- int maxVal = -10001;
- for (int a : nums) {
- minVal = Math.min(minVal, a);
- maxVal = Math.max(maxVal, a);
- }
- int range = maxVal - (minVal - 1) + 1;
- int offset = -(minVal - 1);
- FenwickTree bit = new FenwickTree(range);
- LinkedList ans = new LinkedList<>();
- for (int n = nums.length, i = n - 1; i >= 0; i--) {
- bit.update(offset + nums[i], 1);
- ans.addFirst(bit.ps(offset + nums[i] - 1));
- }
- return ans;
- }
-
- private static class FenwickTree {
- // binary index tree, index 0 is not used
- int[] bit;
- int n;
-
- public FenwickTree(int n) {
- this.n = n + 1;
- this.bit = new int[this.n];
- }
-
- public void update(int i, int v) {
- for (; i < n; i += Integer.lowestOneBit(i)) {
- bit[i] += v;
- }
- }
- // prefix sum query
- private int ps(int j) {
- int ps = 0;
- for (; j != 0; j -= Integer.lowestOneBit(j)) {
- ps += bit[j];
- }
- return ps;
- }
- }
-}
diff --git a/src.save/main/java/g0301_0400/s0316_remove_duplicate_letters/Solution.java b/src.save/main/java/g0301_0400/s0316_remove_duplicate_letters/Solution.java
deleted file mode 100644
index c4f120840..000000000
--- a/src.save/main/java/g0301_0400/s0316_remove_duplicate_letters/Solution.java
+++ /dev/null
@@ -1,43 +0,0 @@
-package g0301_0400.s0316_remove_duplicate_letters;
-
-// #Medium #String #Greedy #Stack #Monotonic_Stack
-// #2022_03_15_Time_2_ms_(98.39%)_Space_42.4_MB_(58.70%)
-
-public class Solution {
- public String removeDuplicateLetters(String s) {
- int[] charCount = new int[26];
- boolean[] charAdded = new boolean[26];
- // Build the char count array
- for (char c : s.toCharArray()) {
- charCount[c - 'a'] += 1;
- }
- StringBuilder sb = new StringBuilder();
- // i = index of the input string
- // j = index of the output stringBuilder
- int j = 0;
- for (int i = 0; i < s.length(); i++) {
- char curr = s.charAt(i);
- // If the curr char is NOT already added in the final string
- if (!charAdded[curr - 'a']) {
- // If the prev char in final string is lexicographically greater than curr char of
- // input string
- // And there are more characters in charCount array then we can remove this prev
- // char from final string
- // Do this check iteratively until all characters are removed from the final string
- // or prev char < curr char
- while (j > 0 && sb.charAt(j - 1) > curr && charCount[sb.charAt(j - 1) - 'a'] > 0) {
- charAdded[sb.charAt(j - 1) - 'a'] = false;
- sb.deleteCharAt(j - 1);
- j--;
- }
- // Add the curr char in final string and mark that character as added in the string
- sb.append(curr);
- charAdded[curr - 'a'] = true;
- j++;
- }
- // Reduce the count of the current character from the charCount array
- charCount[curr - 'a'] -= 1;
- }
- return sb.toString();
- }
-}
diff --git a/src.save/main/java/g0301_0400/s0318_maximum_product_of_word_lengths/Solution.java b/src.save/main/java/g0301_0400/s0318_maximum_product_of_word_lengths/Solution.java
deleted file mode 100644
index d52f31730..000000000
--- a/src.save/main/java/g0301_0400/s0318_maximum_product_of_word_lengths/Solution.java
+++ /dev/null
@@ -1,31 +0,0 @@
-package g0301_0400.s0318_maximum_product_of_word_lengths;
-
-// #Medium #Array #String #Bit_Manipulation #2022_03_15_Time_10_ms_(81.97%)_Space_45.8_MB_(58.85%)
-
-public class Solution {
- public int maxProduct(String[] words) {
- int n = words.length;
- int res = 0;
- int[] masks = new int[n];
- for (int i = 0; i < n; i++) {
- masks[i] = getMask(words[i]);
- }
- for (int i = 0; i < n; i++) {
- for (int j = i + 1; j < n; j++) {
- if ((masks[i] & masks[j]) == 0) {
- res = Math.max(res, words[i].length() * words[j].length());
- }
- }
- }
- return res;
- }
-
- private int getMask(String s) {
- int mask = 0;
- for (int i = 0; i < s.length(); i++) {
- char c = s.charAt(i);
- mask = mask | (1 << (c - 'a'));
- }
- return mask;
- }
-}
diff --git a/src.save/main/java/g0301_0400/s0319_bulb_switcher/Solution.java b/src.save/main/java/g0301_0400/s0319_bulb_switcher/Solution.java
deleted file mode 100644
index 19aac2303..000000000
--- a/src.save/main/java/g0301_0400/s0319_bulb_switcher/Solution.java
+++ /dev/null
@@ -1,12 +0,0 @@
-package g0301_0400.s0319_bulb_switcher;
-
-// #Medium #Math #Brainteaser #2022_03_15_Time_0_ms_(100.00%)_Space_40.5_MB_(57.80%)
-
-public class Solution {
- public int bulbSwitch(int n) {
- if (n < 2) {
- return n;
- }
- return (int) Math.sqrt(n);
- }
-}
diff --git a/src.save/main/java/g0301_0400/s0321_create_maximum_number/Solution.java b/src.save/main/java/g0301_0400/s0321_create_maximum_number/Solution.java
deleted file mode 100644
index 5dce89ec8..000000000
--- a/src.save/main/java/g0301_0400/s0321_create_maximum_number/Solution.java
+++ /dev/null
@@ -1,93 +0,0 @@
-package g0301_0400.s0321_create_maximum_number;
-
-// #Hard #Greedy #Stack #Monotonic_Stack #2022_03_15_Time_9_ms_(93.46%)_Space_46.3_MB_(74.23%)
-
-public class Solution {
- public int[] maxNumber(int[] nums1, int[] nums2, int k) {
- if (k == 0) {
- return new int[0];
- }
- int[] maxSubNums1 = new int[k];
- int[] maxSubNums2 = new int[k];
- int[] res = new int[k];
- // select l elements from nums1
- for (int l = 0; l <= Math.min(k, nums1.length); l++) {
- if (l + nums2.length < k) {
- continue;
- }
- // create maximum number for each array
- // nums1: l elements; nums2: k - l elements
- maxSubArray(nums1, maxSubNums1, l);
- maxSubArray(nums2, maxSubNums2, k - l);
- // merge the two maximum numbers
- // if get a larger number than res, update res
- res = merge(maxSubNums1, maxSubNums2, l, k - l, res);
- }
- return res;
- }
-
- private void maxSubArray(int[] nums, int[] maxSub, int size) {
- if (size == 0) {
- return;
- }
- int j = 0;
- for (int i = 0; i < nums.length; i++) {
- while (j > 0 && nums.length - i + j > size && nums[i] > maxSub[j - 1]) {
- j--;
- }
- if (j < size) {
- maxSub[j++] = nums[i];
- }
- }
- }
-
- private int[] merge(int[] maxSub1, int[] maxSub2, int size1, int size2, int[] res) {
- int[] merge = new int[res.length];
- int i = 0;
- int j = 0;
- int idx = 0;
- boolean equal = true;
- while (i < size1 || j < size2) {
- if (j >= size2) {
- merge[idx] = maxSub1[i++];
- } else if (i >= size1) {
- merge[idx] = maxSub2[j++];
- } else {
- int ii = i;
- int jj = j;
- while (ii < size1 && jj < size2 && maxSub1[ii] == maxSub2[jj]) {
- ii++;
- jj++;
- }
- if (ii < size1 && jj < size2) {
- if (maxSub1[ii] > maxSub2[jj]) {
- merge[idx] = maxSub1[i++];
- } else {
- merge[idx] = maxSub2[j++];
- }
- } else if (jj == size2) {
- merge[idx] = maxSub1[i++];
- } else {
- // ii == size1
- merge[idx] = maxSub2[j++];
- }
- }
- // break if we already know merge must be < res
- if (merge[idx] > res[idx]) {
- equal = false;
- } else if (equal && merge[idx] < res[idx]) {
- break;
- }
- idx++;
- }
- // if get a larger number than res, update res
- int k = res.length;
- if (i == size1 && j == size2 && !equal) {
- return merge;
- }
- if (equal && merge[k - 1] > res[k - 1]) {
- return merge;
- }
- return res;
- }
-}
diff --git a/src.save/main/java/g0301_0400/s0322_coin_change/Solution.java b/src.save/main/java/g0301_0400/s0322_coin_change/Solution.java
deleted file mode 100644
index c72b4a794..000000000
--- a/src.save/main/java/g0301_0400/s0322_coin_change/Solution.java
+++ /dev/null
@@ -1,25 +0,0 @@
-package g0301_0400.s0322_coin_change;
-
-// #Medium #Top_100_Liked_Questions #Top_Interview_Questions #Array #Dynamic_Programming
-// #Breadth_First_Search #Algorithm_II_Day_18_Dynamic_Programming #Dynamic_Programming_I_Day_20
-// #2022_03_15_Time_22_ms_(72.14%)_Space_44.8_MB_(58.75%)
-
-public class Solution {
- public int coinChange(int[] coins, int amount) {
- int[] dp = new int[amount + 1];
- dp[0] = 1;
- for (int coin : coins) {
- for (int i = coin; i <= amount; i++) {
- int prev = dp[i - coin];
- if (prev > 0) {
- if (dp[i] == 0) {
- dp[i] = prev + 1;
- } else {
- dp[i] = Math.min(dp[i], prev + 1);
- }
- }
- }
- }
- return dp[amount] - 1;
- }
-}
diff --git a/src.save/main/java/g0301_0400/s0324_wiggle_sort_ii/Solution.java b/src.save/main/java/g0301_0400/s0324_wiggle_sort_ii/Solution.java
deleted file mode 100644
index bacc737c2..000000000
--- a/src.save/main/java/g0301_0400/s0324_wiggle_sort_ii/Solution.java
+++ /dev/null
@@ -1,31 +0,0 @@
-package g0301_0400.s0324_wiggle_sort_ii;
-
-// #Medium #Top_Interview_Questions #Array #Sorting #Divide_and_Conquer #Quickselect
-// #2022_03_15_Time_6_ms_(69.23%)_Space_56.2_MB_(21.55%)
-
-import java.util.Arrays;
-
-public class Solution {
- public void wiggleSort(int[] nums) {
- Arrays.sort(nums);
- int[] result = new int[nums.length];
- int index = nums.length - 1;
- int i = 1;
- // Start filling all peaks (which is all at odd indexes) from start
- for (; i < nums.length; i += 2) {
- result[i] = nums[index];
- --index;
- }
-
- // Start filling all valleys (which is all at even indexes) from end
- // why from end, as the last peak index may have smallest largest value, so to
- // make sure, that is also '>', fill in the smallest element near it.
- i = ((nums.length - 1) % 2 == 0) ? nums.length - 1 : nums.length - 2;
- index = 0;
- for (; i >= 0; i -= 2) {
- result[i] = nums[index];
- ++index;
- }
- System.arraycopy(result, 0, nums, 0, nums.length);
- }
-}
diff --git a/src.save/main/java/g0301_0400/s0326_power_of_three/Solution.java b/src.save/main/java/g0301_0400/s0326_power_of_three/Solution.java
deleted file mode 100644
index c42ba3b40..000000000
--- a/src.save/main/java/g0301_0400/s0326_power_of_three/Solution.java
+++ /dev/null
@@ -1,20 +0,0 @@
-package g0301_0400.s0326_power_of_three;
-
-// #Easy #Top_Interview_Questions #Math #Recursion
-// #2022_03_15_Time_18_ms_(79.91%)_Space_47.4_MB_(35.85%)
-
-public class Solution {
- // regular method that has a loop
- public boolean isPowerOfThree(int n) {
- if (n < 3 && n != 1) {
- return false;
- }
- while (n != 1) {
- if (n % 3 != 0) {
- return false;
- }
- n /= 3;
- }
- return true;
- }
-}
diff --git a/src.save/main/java/g0301_0400/s0327_count_of_range_sum/Solution.java b/src.save/main/java/g0301_0400/s0327_count_of_range_sum/Solution.java
deleted file mode 100644
index 776627366..000000000
--- a/src.save/main/java/g0301_0400/s0327_count_of_range_sum/Solution.java
+++ /dev/null
@@ -1,46 +0,0 @@
-package g0301_0400.s0327_count_of_range_sum;
-
-// #Hard #Array #Binary_Search #Ordered_Set #Divide_and_Conquer #Segment_Tree #Binary_Indexed_Tree
-// #Merge_Sort #2022_03_15_Time_64_ms_(87.41%)_Space_55.5_MB_(89.38%)
-
-public class Solution {
- public int countRangeSum(int[] nums, int lower, int upper) {
- int n = nums.length;
- long[] sums = new long[n + 1];
- for (int i = 0; i < n; i++) {
- sums[i + 1] = sums[i] + nums[i];
- }
- return countWhileMergeSort(sums, 0, n + 1, lower, upper);
- }
-
- private int countWhileMergeSort(long[] sums, int start, int end, int lower, int upper) {
- if (end - start <= 1) {
- return 0;
- }
- int mid = (start + end) / 2;
- int count =
- countWhileMergeSort(sums, start, mid, lower, upper)
- + countWhileMergeSort(sums, mid, end, lower, upper);
- int j = mid;
- int k = mid;
- int t = mid;
- long[] cache = new long[end - start];
- int r = 0;
- for (int i = start; i < mid; i++) {
- while (k < end && sums[k] - sums[i] < lower) {
- k++;
- }
- while (j < end && sums[j] - sums[i] <= upper) {
- j++;
- }
- while (t < end && sums[t] < sums[i]) {
- cache[r++] = sums[t++];
- }
- cache[r] = sums[i];
- count += j - k;
- r++;
- }
- System.arraycopy(cache, 0, sums, start, t - start);
- return count;
- }
-}
diff --git a/src.save/main/java/g0301_0400/s0328_odd_even_linked_list/Solution.java b/src.save/main/java/g0301_0400/s0328_odd_even_linked_list/Solution.java
deleted file mode 100644
index 7728e9d32..000000000
--- a/src.save/main/java/g0301_0400/s0328_odd_even_linked_list/Solution.java
+++ /dev/null
@@ -1,35 +0,0 @@
-package g0301_0400.s0328_odd_even_linked_list;
-
-// #Medium #Top_Interview_Questions #Linked_List
-// #2022_03_15_Time_0_ms_(100.00%)_Space_41.7_MB_(79.98%)
-
-import com_github_leetcode.ListNode;
-
-/*
- * Definition for singly-linked list.
- * public class ListNode {
- * int val;
- * ListNode next;
- * ListNode() {}
- * ListNode(int val) { this.val = val; }
- * ListNode(int val, ListNode next) { this.val = val; this.next = next; }
- * }
- */
-public class Solution {
- public ListNode oddEvenList(ListNode head) {
- if (head != null) {
- ListNode odd = head;
- ListNode even = head.next;
- ListNode evenHead = even;
- while (even != null && even.next != null) {
- odd.next = odd.next.next;
- even.next = even.next.next;
- odd = odd.next;
- even = even.next;
- }
-
- odd.next = evenHead;
- }
- return head;
- }
-}
diff --git a/src.save/main/java/g0301_0400/s0329_longest_increasing_path_in_a_matrix/Solution.java b/src.save/main/java/g0301_0400/s0329_longest_increasing_path_in_a_matrix/Solution.java
deleted file mode 100644
index f638b643c..000000000
--- a/src.save/main/java/g0301_0400/s0329_longest_increasing_path_in_a_matrix/Solution.java
+++ /dev/null
@@ -1,44 +0,0 @@
-package g0301_0400.s0329_longest_increasing_path_in_a_matrix;
-
-// #Hard #Top_Interview_Questions #Dynamic_Programming #Depth_First_Search #Breadth_First_Search
-// #Graph #Memoization #Topological_Sort #2022_03_15_Time_8_ms_(91.02%)_Space_54.2_MB_(33.62%)
-
-public class Solution {
- public int longestIncreasingPath(int[][] matrix) {
- int maxIncreasingSequenceCount = 0;
- int n = matrix.length - 1;
- int m = matrix[0].length - 1;
- int[][] memory = new int[n + 1][m + 1];
- for (int i = 0; i < matrix.length; i++) {
- for (int j = 0; j < matrix[i].length; j++) {
- maxIncreasingSequenceCount =
- Math.max(maxIncreasingSequenceCount, move(i, j, n, m, matrix, memory));
- }
- }
- return maxIncreasingSequenceCount;
- }
-
- private int move(int row, int col, int n, int m, int[][] matrix, int[][] memory) {
- if (memory[row][col] == 0) {
- int count = 1;
- // move down
- if (row < n && matrix[row + 1][col] > matrix[row][col]) {
- count = Math.max(count, move(row + 1, col, n, m, matrix, memory) + 1);
- }
- // move right
- if (col < m && matrix[row][col + 1] > matrix[row][col]) {
- count = Math.max(count, move(row, col + 1, n, m, matrix, memory) + 1);
- }
- // move up
- if (row > 0 && matrix[row - 1][col] > matrix[row][col]) {
- count = Math.max(count, move(row - 1, col, n, m, matrix, memory) + 1);
- }
- // move left
- if (col > 0 && matrix[row][col - 1] > matrix[row][col]) {
- count = Math.max(count, move(row, col - 1, n, m, matrix, memory) + 1);
- }
- memory[row][col] = count;
- }
- return memory[row][col];
- }
-}
diff --git a/src.save/main/java/g0301_0400/s0330_patching_array/Solution.java b/src.save/main/java/g0301_0400/s0330_patching_array/Solution.java
deleted file mode 100644
index 2204afad0..000000000
--- a/src.save/main/java/g0301_0400/s0330_patching_array/Solution.java
+++ /dev/null
@@ -1,22 +0,0 @@
-package g0301_0400.s0330_patching_array;
-
-// #Hard #Array #Greedy #2022_03_15_Time_0_ms_(100.00%)_Space_44.1_MB_(38.52%)
-
-public class Solution {
- public int minPatches(int[] nums, int n) {
- int res = 0;
- long sum = 0;
- int i = 0;
- while (sum < n) {
- // required number
- long req = sum + 1;
- if (i < nums.length && nums[i] <= req) {
- sum += nums[i++];
- } else {
- sum += req;
- res++;
- }
- }
- return res;
- }
-}
diff --git a/src.save/main/java/g0301_0400/s0331_verify_preorder_serialization_of_a_binary_tree/Solution.java b/src.save/main/java/g0301_0400/s0331_verify_preorder_serialization_of_a_binary_tree/Solution.java
deleted file mode 100644
index da9895c33..000000000
--- a/src.save/main/java/g0301_0400/s0331_verify_preorder_serialization_of_a_binary_tree/Solution.java
+++ /dev/null
@@ -1,20 +0,0 @@
-package g0301_0400.s0331_verify_preorder_serialization_of_a_binary_tree;
-
-// #Medium #String #Tree #Binary_Tree #Stack #2022_03_15_Time_3_ms_(94.01%)_Space_42.7_MB_(58.33%)
-
-public class Solution {
- public boolean isValidSerialization(String preorder) {
- int count = 1;
- int length = preorder.length();
- for (int i = 1; i <= length; i++) {
- if (i == length || preorder.charAt(i) == ',') {
- --count;
- if (count < 0) {
- return false;
- }
- count += preorder.charAt(i - 1) == '#' ? 0 : 2;
- }
- }
- return count == 0;
- }
-}
diff --git a/src.save/main/java/g0301_0400/s0332_reconstruct_itinerary/Solution.java b/src.save/main/java/g0301_0400/s0332_reconstruct_itinerary/Solution.java
deleted file mode 100644
index 34d9ab955..000000000
--- a/src.save/main/java/g0301_0400/s0332_reconstruct_itinerary/Solution.java
+++ /dev/null
@@ -1,35 +0,0 @@
-package g0301_0400.s0332_reconstruct_itinerary;
-
-// #Hard #Depth_First_Search #Graph #Eulerian_Circuit
-// #2022_03_15_Time_11_ms_(47.68%)_Space_50.5_MB_(23.60%)
-
-import java.util.HashMap;
-import java.util.LinkedList;
-import java.util.List;
-import java.util.Map;
-import java.util.PriorityQueue;
-
-public class Solution {
- public List findItinerary(List> tickets) {
- HashMap> map = new HashMap<>();
- LinkedList ans = new LinkedList<>();
- for (List ticket : tickets) {
- String src = ticket.get(0);
- String dest = ticket.get(1);
- PriorityQueue pq = map.getOrDefault(src, new PriorityQueue<>());
- pq.add(dest);
- map.put(src, pq);
- }
- dfs(map, "JFK", ans);
- return ans;
- }
-
- private void dfs(Map> map, String src, LinkedList ans) {
- PriorityQueue temp = map.get(src);
- while (temp != null && !temp.isEmpty()) {
- String nbr = temp.remove();
- dfs(map, nbr, ans);
- }
- ans.addFirst(src);
- }
-}
diff --git a/src.save/main/java/g0301_0400/s0334_increasing_triplet_subsequence/Solution.java b/src.save/main/java/g0301_0400/s0334_increasing_triplet_subsequence/Solution.java
deleted file mode 100644
index fda4b00e9..000000000
--- a/src.save/main/java/g0301_0400/s0334_increasing_triplet_subsequence/Solution.java
+++ /dev/null
@@ -1,23 +0,0 @@
-package g0301_0400.s0334_increasing_triplet_subsequence;
-
-// #Medium #Top_Interview_Questions #Array #Greedy #Data_Structure_II_Day_5_Array
-// #2022_03_15_Time_3_ms_(61.85%)_Space_94.1_MB_(22.67%)
-
-public class Solution {
- public boolean increasingTriplet(int[] nums) {
- int n = nums.length;
- int i = 0;
- int low = Integer.MAX_VALUE;
- int high = Integer.MAX_VALUE;
- while (i < n) {
- if (low >= nums[i]) {
- low = nums[i++];
- } else if (high >= nums[i]) {
- high = nums[i++];
- } else {
- return true;
- }
- }
- return false;
- }
-}
diff --git a/src.save/main/java/g0301_0400/s0335_self_crossing/Solution.java b/src.save/main/java/g0301_0400/s0335_self_crossing/Solution.java
deleted file mode 100644
index 876fed5da..000000000
--- a/src.save/main/java/g0301_0400/s0335_self_crossing/Solution.java
+++ /dev/null
@@ -1,27 +0,0 @@
-package g0301_0400.s0335_self_crossing;
-
-// #Hard #Array #Math #Geometry #2022_03_15_Time_6_ms_(44.12%)_Space_51.3_MB_(52.94%)
-
-public class Solution {
- public boolean isSelfCrossing(int[] x) {
- if (x.length < 4) {
- return false;
- }
- for (int i = 3; i < x.length; i++) {
- if (x[i - 1] <= x[i - 3] && x[i] >= x[i - 2]) {
- return true;
- }
- if (i > 4
- && x[i] >= x[i - 2] - x[i - 4]
- && x[i - 1] >= x[i - 3] - x[i - 5]
- && x[i - 1] <= x[i - 3]
- && x[i - 2] >= x[i - 4]) {
- return true;
- }
- if (i > 3 && x[i - 1] == x[i - 3] && x[i] >= x[i - 2] - x[i - 4]) {
- return true;
- }
- }
- return false;
- }
-}
diff --git a/src.save/main/java/g0301_0400/s0336_palindrome_pairs/Solution.java b/src.save/main/java/g0301_0400/s0336_palindrome_pairs/Solution.java
deleted file mode 100644
index 0484dae31..000000000
--- a/src.save/main/java/g0301_0400/s0336_palindrome_pairs/Solution.java
+++ /dev/null
@@ -1,79 +0,0 @@
-package g0301_0400.s0336_palindrome_pairs;
-
-// #Hard #Array #String #Hash_Table #Trie #2022_03_15_Time_1219_ms_(54.97%)_Space_248.7_MB_(55.27%)
-
-import java.util.ArrayList;
-import java.util.Arrays;
-import java.util.List;
-
-public class Solution {
- private static class TrieNode {
- TrieNode[] next;
- int index;
- List list;
-
- TrieNode() {
- next = new TrieNode[26];
- index = -1;
- list = new ArrayList<>();
- }
- }
-
- public List> palindromePairs(String[] words) {
- List> res = new ArrayList<>();
- TrieNode root = new TrieNode();
- for (int i = 0; i < words.length; i++) {
- addWord(root, words[i], i);
- }
- for (int i = 0; i < words.length; i++) {
- search(words, i, root, res);
- }
- return res;
- }
-
- private void addWord(TrieNode root, String word, int index) {
- for (int i = word.length() - 1; i >= 0; i--) {
- int j = word.charAt(i) - 'a';
- if (root.next[j] == null) {
- root.next[j] = new TrieNode();
- }
- if (isPalindrome(word, 0, i)) {
- root.list.add(index);
- }
- root = root.next[j];
- }
- root.list.add(index);
- root.index = index;
- }
-
- private void search(String[] words, int i, TrieNode root, List> res) {
- for (int j = 0; j < words[i].length(); j++) {
- if (root.index >= 0
- && root.index != i
- && isPalindrome(words[i], j, words[i].length() - 1)) {
- res.add(Arrays.asList(i, root.index));
- }
-
- root = root.next[words[i].charAt(j) - 'a'];
- if (root == null) {
- return;
- }
- }
-
- for (int j : root.list) {
- if (i == j) {
- continue;
- }
- res.add(Arrays.asList(i, j));
- }
- }
-
- private boolean isPalindrome(String word, int i, int j) {
- while (i < j) {
- if (word.charAt(i++) != word.charAt(j--)) {
- return false;
- }
- }
- return true;
- }
-}
diff --git a/src.save/main/java/g0301_0400/s0337_house_robber_iii/Solution.java b/src.save/main/java/g0301_0400/s0337_house_robber_iii/Solution.java
deleted file mode 100644
index 0f9e38ea2..000000000
--- a/src.save/main/java/g0301_0400/s0337_house_robber_iii/Solution.java
+++ /dev/null
@@ -1,44 +0,0 @@
-package g0301_0400.s0337_house_robber_iii;
-
-// #Medium #Top_100_Liked_Questions #Dynamic_Programming #Depth_First_Search #Tree #Binary_Tree
-// #2022_03_15_Time_1_ms_(87.96%)_Space_44.1_MB_(55.84%)
-
-import com_github_leetcode.TreeNode;
-
-/*
- * Definition for a binary tree node.
- * public class TreeNode {
- * int val;
- * TreeNode left;
- * TreeNode right;
- * TreeNode() {}
- * TreeNode(int val) { this.val = val; }
- * TreeNode(int val, TreeNode left, TreeNode right) {
- * this.val = val;
- * this.left = left;
- * this.right = right;
- * }
- * }
- */
-public class Solution {
- public int rob(TreeNode root) {
- int[] out = robRec(root);
- return Math.max(out[0], out[1]);
- }
-
- private int[] robRec(TreeNode curr) {
- if (curr == null) {
- return new int[] {0, 0};
- }
- int[] left = robRec(curr.left);
- int[] right = robRec(curr.right);
- int[] out = new int[2];
- // 1. If choosing to take the house
- out[0] = curr.val + left[1] + right[1];
- // 2. If choosing to skip the house
- out[1] = left[0] + right[0];
- // 3. Best Solution at house
- out[0] = Math.max(out[0], out[1]);
- return out;
- }
-}
diff --git a/src.save/main/java/g0301_0400/s0338_counting_bits/Solution.java b/src.save/main/java/g0301_0400/s0338_counting_bits/Solution.java
deleted file mode 100644
index 47e7b9fd9..000000000
--- a/src.save/main/java/g0301_0400/s0338_counting_bits/Solution.java
+++ /dev/null
@@ -1,23 +0,0 @@
-package g0301_0400.s0338_counting_bits;
-
-// #Easy #Dynamic_Programming #Bit_Manipulation
-// #2022_03_15_Time_1_ms_(99.97%)_Space_46.6_MB_(76.56%)
-
-public class Solution {
- public int[] countBits(int num) {
- int[] result = new int[num + 1];
- int borderPos = 1;
- int incrPos = 1;
- for (int i = 1; i < result.length; i++) {
- // when we reach pow of 2 , reset borderPos and incrPos
- if (incrPos == borderPos) {
- result[i] = 1;
- incrPos = 1;
- borderPos = i;
- } else {
- result[i] = 1 + result[incrPos++];
- }
- }
- return result;
- }
-}
diff --git a/src.save/main/java/g0301_0400/s0342_power_of_four/Solution.java b/src.save/main/java/g0301_0400/s0342_power_of_four/Solution.java
deleted file mode 100644
index 1bdc0a662..000000000
--- a/src.save/main/java/g0301_0400/s0342_power_of_four/Solution.java
+++ /dev/null
@@ -1,16 +0,0 @@
-package g0301_0400.s0342_power_of_four;
-
-// #Easy #Math #Bit_Manipulation #Recursion #2022_03_15_Time_1_ms_(91.73%)_Space_41.4_MB_(30.80%)
-
-public class Solution {
- public boolean isPowerOfFour(int n) {
- while (n >= 4) {
- if (n % 4 != 0) {
- return false;
- }
- n = n / 4;
- }
-
- return n == 1;
- }
-}
diff --git a/src.save/main/java/g0301_0400/s0343_integer_break/Solution.java b/src.save/main/java/g0301_0400/s0343_integer_break/Solution.java
deleted file mode 100644
index a095c0224..000000000
--- a/src.save/main/java/g0301_0400/s0343_integer_break/Solution.java
+++ /dev/null
@@ -1,30 +0,0 @@
-package g0301_0400.s0343_integer_break;
-
-// #Medium #Dynamic_Programming #Math #Algorithm_II_Day_18_Dynamic_Programming
-// #Dynamic_Programming_I_Day_21 #2022_03_15_Time_0_ms_(100.00%)_Space_41.8_MB_(5.24%)
-
-public class Solution {
- private int[] arr;
-
- public int integerBreak(int n) {
- arr = new int[n + 1];
- arr[2] = 1;
- // only case involve with 1 other than 2 is 3
- return n == 3 ? 2 : dp(n);
- }
-
- private int dp(int n) {
- if (n <= 2) {
- return arr[2];
- } else if (arr[n] != 0) {
- return arr[n];
- } else {
- int prod = 1;
- for (int i = 2; i <= n; i++) {
- prod = Math.max(prod, i * dp(n - i));
- }
- arr[n] = prod;
- }
- return arr[n];
- }
-}
diff --git a/src.save/main/java/g0301_0400/s0344_reverse_string/Solution.java b/src.save/main/java/g0301_0400/s0344_reverse_string/Solution.java
deleted file mode 100644
index dbc5d3ef2..000000000
--- a/src.save/main/java/g0301_0400/s0344_reverse_string/Solution.java
+++ /dev/null
@@ -1,16 +0,0 @@
-package g0301_0400.s0344_reverse_string;
-
-// #Easy #Top_Interview_Questions #String #Two_Pointers #Recursion #Algorithm_I_Day_4_Two_Pointers
-// #2022_03_15_Time_1_ms_(87.94%)_Space_54.6_MB_(42.01%)
-
-public class Solution {
- public void reverseString(char[] s) {
- int left = 0;
- int right = s.length - 1;
- while (left < right) {
- char tmp = s[left];
- s[left++] = s[right];
- s[right--] = tmp;
- }
- }
-}
diff --git a/src.save/main/java/g0301_0400/s0345_reverse_vowels_of_a_string/Solution.java b/src.save/main/java/g0301_0400/s0345_reverse_vowels_of_a_string/Solution.java
deleted file mode 100644
index 299ad4c3e..000000000
--- a/src.save/main/java/g0301_0400/s0345_reverse_vowels_of_a_string/Solution.java
+++ /dev/null
@@ -1,31 +0,0 @@
-package g0301_0400.s0345_reverse_vowels_of_a_string;
-
-// #Easy #String #Two_Pointers #2022_03_15_Time_4_ms_(86.90%)_Space_45.3_MB_(37.34%)
-
-public class Solution {
- private boolean isVowel(char c) {
- return c == 'a' || c == 'A' || c == 'e' || c == 'E' || c == 'i' || c == 'I' || c == 'o'
- || c == 'O' || c == 'u' || c == 'U';
- }
-
- public String reverseVowels(String str) {
- int i = 0;
- int j = str.length() - 1;
- char[] str1 = str.toCharArray();
- while (i < j) {
- if (!isVowel(str1[i])) {
- i++;
- } else if (!isVowel(str1[j])) {
- j--;
- } else {
- // swapping
- char t = str1[i];
- str1[i] = str1[j];
- str1[j] = t;
- i++;
- j--;
- }
- }
- return String.copyValueOf(str1);
- }
-}
diff --git a/src.save/main/java/g0301_0400/s0347_top_k_frequent_elements/Solution.java b/src.save/main/java/g0301_0400/s0347_top_k_frequent_elements/Solution.java
deleted file mode 100644
index e9ee54650..000000000
--- a/src.save/main/java/g0301_0400/s0347_top_k_frequent_elements/Solution.java
+++ /dev/null
@@ -1,35 +0,0 @@
-package g0301_0400.s0347_top_k_frequent_elements;
-
-// #Medium #Top_100_Liked_Questions #Top_Interview_Questions #Array #Hash_Table #Sorting
-// #Heap_Priority_Queue #Counting #Divide_and_Conquer #Quickselect #Bucket_Sort
-// #Data_Structure_II_Day_20_Heap_Priority_Queue
-// #2022_03_15_Time_7_ms_(99.54%)_Space_44.9_MB_(85.23%)
-
-import java.util.Arrays;
-import java.util.PriorityQueue;
-import java.util.Queue;
-
-public class Solution {
- public int[] topKFrequent(int[] nums, int k) {
- Arrays.sort(nums);
- // Min heap of
- Queue queue = new PriorityQueue<>(k + 1, (a, b) -> (a[1] - b[1]));
- // Filter with min heap
- int j = 0;
- for (int i = 0; i <= nums.length; i++) {
- if (i == nums.length || nums[i] != nums[j]) {
- queue.offer(new int[] {nums[j], i - j});
- if (queue.size() > k) {
- queue.poll();
- }
- j = i;
- }
- }
- // Convert to int array
- int[] result = new int[k];
- for (int i = k - 1; i >= 0; i--) {
- result[i] = queue.poll()[0];
- }
- return result;
- }
-}
diff --git a/src.save/main/java/g0301_0400/s0349_intersection_of_two_arrays/Solution.java b/src.save/main/java/g0301_0400/s0349_intersection_of_two_arrays/Solution.java
deleted file mode 100644
index 8bebb3cda..000000000
--- a/src.save/main/java/g0301_0400/s0349_intersection_of_two_arrays/Solution.java
+++ /dev/null
@@ -1,28 +0,0 @@
-package g0301_0400.s0349_intersection_of_two_arrays;
-
-// #Easy #Array #Hash_Table #Sorting #Binary_Search #Two_Pointers
-// #2022_03_15_Time_1_ms_(99.75%)_Space_43.9_MB_(40.34%)
-
-import java.util.ArrayList;
-import java.util.List;
-
-public class Solution {
- public int[] intersection(int[] nums1, int[] nums2) {
- boolean[] occ = new boolean[1001];
- for (int k : nums1) {
- occ[k] = true;
- }
- List res = new ArrayList<>();
- for (int j : nums2) {
- if (occ[j]) {
- occ[j] = false;
- res.add(j);
- }
- }
- int[] result = new int[res.size()];
- for (int i = 0; i < res.size(); i++) {
- result[i] = res.get(i);
- }
- return result;
- }
-}
diff --git a/src.save/main/java/g0301_0400/s0350_intersection_of_two_arrays_ii/Solution.java b/src.save/main/java/g0301_0400/s0350_intersection_of_two_arrays_ii/Solution.java
deleted file mode 100644
index 6827f2b4d..000000000
--- a/src.save/main/java/g0301_0400/s0350_intersection_of_two_arrays_ii/Solution.java
+++ /dev/null
@@ -1,41 +0,0 @@
-package g0301_0400.s0350_intersection_of_two_arrays_ii;
-
-// #Easy #Top_Interview_Questions #Array #Hash_Table #Sorting #Binary_Search #Two_Pointers
-// #Data_Structure_I_Day_3_Array #2022_03_15_Time_3_ms_(81.79%)_Space_43.8_MB_(46.55%)
-
-import java.util.Arrays;
-
-public class Solution {
- public int[] intersect(int[] nums1, int[] nums2) {
- // First sort the array
- Arrays.sort(nums1);
- // Similar this one as well
- Arrays.sort(nums2);
- // "i" will point at nums1
- int i = 0;
- // "j" will point at nums2
- int j = 0;
- // "k" will point at nums1 and helps in getting the intersection answer;
- int k = 0;
- // Loop will run until "i" & "j" doesn't reach the array boundary;
- while (i < nums1.length && j < nums2.length) {
- if (nums1[i] < nums2[j]) {
- // Check if nums1 value is less then nums2 value;
- // Increment "i"
- i++;
- } else if (nums1[i] > nums2[j]) {
- // Check if nums2 value is less then nums1 value;
- // Increment "j"
- j++;
-
- } else {
- // Check if nums1 value is equals to nums2 value;
- // Dump into nums1 and increment k, increment i & increment j as well;
- nums1[k++] = nums1[i++];
- j++;
- }
- }
- // Only return nums1 0th index to kth index value, because that's will be our intersection;
- return Arrays.copyOfRange(nums1, 0, k);
- }
-}
diff --git a/src.save/main/java/g0301_0400/s0354_russian_doll_envelopes/Solution.java b/src.save/main/java/g0301_0400/s0354_russian_doll_envelopes/Solution.java
deleted file mode 100644
index 8272ff09b..000000000
--- a/src.save/main/java/g0301_0400/s0354_russian_doll_envelopes/Solution.java
+++ /dev/null
@@ -1,31 +0,0 @@
-package g0301_0400.s0354_russian_doll_envelopes;
-
-// #Hard #Array #Dynamic_Programming #Sorting #Binary_Search
-// #2022_03_15_Time_65_ms_(67.49%)_Space_73.9_MB_(66.98%)
-
-import java.util.Arrays;
-
-public class Solution {
- public int maxEnvelopes(int[][] envelopes) {
- Arrays.sort(envelopes, (a, b) -> a[0] != b[0] ? a[0] - b[0] : b[1] - a[1]);
- int[] tails = new int[envelopes.length];
- int size = 0;
- for (int[] enve : envelopes) {
- int i = 0;
- int j = size;
- while (i != j) {
- int mid = i + ((j - i) >> 1);
- if (tails[mid] < enve[1]) {
- i = mid + 1;
- } else {
- j = mid;
- }
- }
- tails[i] = enve[1];
- if (i == size) {
- size++;
- }
- }
- return size;
- }
-}
diff --git a/src.save/main/java/g0301_0400/s0357_count_numbers_with_unique_digits/Solution.java b/src.save/main/java/g0301_0400/s0357_count_numbers_with_unique_digits/Solution.java
deleted file mode 100644
index 809a85d88..000000000
--- a/src.save/main/java/g0301_0400/s0357_count_numbers_with_unique_digits/Solution.java
+++ /dev/null
@@ -1,18 +0,0 @@
-package g0301_0400.s0357_count_numbers_with_unique_digits;
-
-// #Medium #Dynamic_Programming #Math #Backtracking
-// #2022_03_15_Time_0_ms_(100.00%)_Space_39_MB_(73.67%)
-
-public class Solution {
- public int countNumbersWithUniqueDigits(int n) {
- int ans = 1;
- for (int i = 1; i <= n; i++) {
- int mul = 1;
- for (int j = 1; j < i; j++) {
- mul *= (10 - j);
- }
- ans = ans + 9 * mul;
- }
- return ans;
- }
-}
diff --git a/src.save/main/java/g0301_0400/s0363_max_sum_of_rectangle_no_larger_than_k/Solution.java b/src.save/main/java/g0301_0400/s0363_max_sum_of_rectangle_no_larger_than_k/Solution.java
deleted file mode 100644
index d666e315d..000000000
--- a/src.save/main/java/g0301_0400/s0363_max_sum_of_rectangle_no_larger_than_k/Solution.java
+++ /dev/null
@@ -1,49 +0,0 @@
-package g0301_0400.s0363_max_sum_of_rectangle_no_larger_than_k;
-
-// #Hard #Array #Dynamic_Programming #Binary_Search #Matrix #Ordered_Set
-// #2022_03_15_Time_69_ms_(97.33%)_Space_49.4_MB_(73.79%)
-
-public class Solution {
- public int maxSumSubmatrix(int[][] matrix, int k) {
- if (matrix == null || matrix.length == 0 || matrix[0].length == 0) {
- return 0;
- }
- int row = matrix.length;
- int col = matrix[0].length;
- int res = Integer.MIN_VALUE;
- for (int i = 0; i < col; i++) {
- int[] sum = new int[row];
- for (int j = i; j < col; j++) {
- for (int r = 0; r < row; r++) {
- sum[r] += matrix[r][j];
- }
- int curr = 0;
- int max = sum[0];
- for (int n : sum) {
- curr = Math.max(n, curr + n);
- max = Math.max(curr, max);
- if (max == k) {
- return max;
- }
- }
- if (max < k) {
- res = Math.max(max, res);
- } else {
- for (int a = 0; a < row; a++) {
- int currSum = 0;
- for (int b = a; b < row; b++) {
- currSum += sum[b];
- if (currSum <= k) {
- res = Math.max(currSum, res);
- }
- }
- }
- if (res == k) {
- return res;
- }
- }
- }
- }
- return res;
- }
-}
diff --git a/src.save/main/java/g0301_0400/s0365_water_and_jug_problem/Solution.java b/src.save/main/java/g0301_0400/s0365_water_and_jug_problem/Solution.java
deleted file mode 100644
index b1fc90a50..000000000
--- a/src.save/main/java/g0301_0400/s0365_water_and_jug_problem/Solution.java
+++ /dev/null
@@ -1,22 +0,0 @@
-package g0301_0400.s0365_water_and_jug_problem;
-
-// #Medium #Math #Depth_First_Search #Breadth_First_Search
-// #Graph_Theory_I_Day_11_Breadth_First_Search
-// #2022_03_15_Time_0_ms_(100.00%)_Space_38.9_MB_(84.92%)
-
-public class Solution {
- private int gcd(int n1, int n2) {
- if (n2 == 0) {
- return n1;
- }
- return gcd(n2, n1 % n2);
- }
-
- public boolean canMeasureWater(int jug1, int jug2, int target) {
- if (jug1 + jug2 < target) {
- return false;
- }
- int gcd = gcd(jug1, jug2);
- return target % gcd == 0;
- }
-}
diff --git a/src.save/main/java/g0301_0400/s0367_valid_perfect_square/Solution.java b/src.save/main/java/g0301_0400/s0367_valid_perfect_square/Solution.java
deleted file mode 100644
index 8a4cbd539..000000000
--- a/src.save/main/java/g0301_0400/s0367_valid_perfect_square/Solution.java
+++ /dev/null
@@ -1,32 +0,0 @@
-package g0301_0400.s0367_valid_perfect_square;
-
-// #Easy #Math #Binary_Search #2022_03_15_Time_0_ms_(100.00%)_Space_41.7_MB_(7.15%)
-
-public class Solution {
- public boolean isPerfectSquare(int num) {
- if (num == 0) {
- // If num is 0 return false
- return false;
- }
- // long datatype can holds huge number.
- long start = 0;
- long end = num;
- long mid = 0;
- while (start <= end) {
- // until start is lesser or equal to end do this
- // Finding middle value
- mid = start + (end - start) / 2;
- if (mid * mid == num) {
- // if mid*mid == num return true
- return true;
- } else if (mid * mid < num) {
- // if num is greater than mid*mid then make start = mid + 1
- start = mid + 1;
- } else if (mid * mid > num) {
- // if num is lesser than mid*mid then make end = mid - 1
- end = mid - 1;
- }
- }
- return false;
- }
-}
diff --git a/src.save/main/java/g0301_0400/s0368_largest_divisible_subset/Solution.java b/src.save/main/java/g0301_0400/s0368_largest_divisible_subset/Solution.java
deleted file mode 100644
index cc838fc80..000000000
--- a/src.save/main/java/g0301_0400/s0368_largest_divisible_subset/Solution.java
+++ /dev/null
@@ -1,62 +0,0 @@
-package g0301_0400.s0368_largest_divisible_subset;
-
-// #Medium #Array #Dynamic_Programming #Math #Sorting
-// #2022_03_15_Time_20_ms_(87.61%)_Space_42.1_MB_(77.48%)
-
-import java.util.ArrayList;
-import java.util.Arrays;
-import java.util.List;
-
-public class Solution {
- // Helper class containing value and an arraylist
- private static class Helper {
- int val;
- List al;
-
- Helper(int val) {
- this.val = val;
- al = new ArrayList<>();
- }
- }
-
- public List largestDivisibleSubset(int[] nums) {
- // Initializing Helper type array
- Helper[] dp = new Helper[nums.length];
- // Sorting given array
- Arrays.sort(nums);
- // max variable will keep track size of Longest Divisible Subset
- int max = 0;
- // index variable will keep track the index at which dp contains Longest Divisible Subset
- int index = 0;
- dp[0] = new Helper(1);
- dp[0].al.add(nums[0]);
- // Operation similar to LIS
- for (int i = 1; i < nums.length; i++) {
- int max2 = 0;
- int pos = i;
- for (int j = 0; j < i; j++) {
- if (nums[i] % nums[j] == 0 && max2 < dp[j].val) {
- max2 = dp[j].val;
- pos = j;
- }
- }
- // max2 = 0, means no element exists which can divide the present element
- if (max2 == 0) {
- dp[i] = new Helper(max2 + 1);
- dp[i].al.add(nums[i]);
- } else {
- dp[i] = new Helper(max2 + 1);
- for (int val : dp[pos].al) {
- dp[i].al.add(val);
- }
- dp[i].al.add(nums[i]);
- }
- if (max2 > max) {
- max = max2;
- index = i;
- }
- }
- // Returning Largest Divisible Subset
- return dp[index].al;
- }
-}
diff --git a/src.save/main/java/g0301_0400/s0371_sum_of_two_integers/Solution.java b/src.save/main/java/g0301_0400/s0371_sum_of_two_integers/Solution.java
deleted file mode 100644
index ebbec34f6..000000000
--- a/src.save/main/java/g0301_0400/s0371_sum_of_two_integers/Solution.java
+++ /dev/null
@@ -1,44 +0,0 @@
-package g0301_0400.s0371_sum_of_two_integers;
-
-// #Medium #Top_Interview_Questions #Math #Bit_Manipulation
-// #2022_03_15_Time_0_ms_(100.00%)_Space_38.7_MB_(77.08%)
-
-public class Solution {
- public int getSum(int a, int b) {
- int ans = 0;
- int memo = 0;
- int exp = 0;
- int count = 0;
- while (count < 32) {
- int val1 = a & 1;
- int val2 = b & 1;
- int val = sum(val1, val2, memo);
- memo = val >> 1;
- val = val & 1;
- a = a >> 1;
- b = b >> 1;
- ans = ans | (val << exp);
- exp = plusOne(exp);
- count = plusOne(count);
- }
- return ans;
- }
-
- private int sum(int val1, int val2, int val3) {
- int count = 0;
- if (val1 == 1) {
- count = plusOne(count);
- }
- if (val2 == 1) {
- count = plusOne(count);
- }
- if (val3 == 1) {
- count = plusOne(count);
- }
- return count;
- }
-
- private int plusOne(int val) {
- return (-(~val));
- }
-}
diff --git a/src.save/main/java/g0301_0400/s0372_super_pow/Solution.java b/src.save/main/java/g0301_0400/s0372_super_pow/Solution.java
deleted file mode 100644
index 3e54afab6..000000000
--- a/src.save/main/java/g0301_0400/s0372_super_pow/Solution.java
+++ /dev/null
@@ -1,70 +0,0 @@
-package g0301_0400.s0372_super_pow;
-
-// #Medium #Math #Divide_and_Conquer #2022_03_15_Time_2_ms_(91.10%)_Space_45.4_MB_(57.63%)
-
-public class Solution {
- private static final int MOD = 1337;
-
- public int superPow(int a, int[] b) {
- int phi = phi(MOD);
- int arrMod = arrMod(b, phi);
- if (isGreaterOrEqual(b, phi)) {
- // Cycle has started
- // cycle starts at phi with length phi
- return exp(a % MOD, phi + arrMod);
- }
- return exp(a % MOD, arrMod);
- }
-
- private int phi(int n) {
- double result = n;
- for (int p = 2; p * p <= n; p++) {
- if (n % p > 0) {
- continue;
- }
- while (n % p == 0) {
- n /= p;
- }
- result *= 1.0 - 1.0 / p;
- }
- if (n > 1) {
- // if starting n was also prime (so it was greater than sqrt(n))
- result *= (1.0 - (1.0 / n));
- }
- return (int) result;
- }
-
- // Returns true if number in array is greater than integer named phi
- private boolean isGreaterOrEqual(int[] b, int phi) {
- int cur = 0;
- for (int j : b) {
- cur = cur * 10 + j;
- if (cur >= phi) {
- return true;
- }
- }
- return false;
- }
-
- // Returns number in array mod phi
- private int arrMod(int[] b, int phi) {
- int res = 0;
- for (int j : b) {
- res = (res * 10 + j) % phi;
- }
- return res;
- }
-
- // Binary exponentiation
- private int exp(int a, int b) {
- int y = 1;
- while (b > 0) {
- if (b % 2 == 1) {
- y = (y * a) % MOD;
- }
- a = (a * a) % MOD;
- b /= 2;
- }
- return y;
- }
-}
diff --git a/src.save/main/java/g0301_0400/s0373_find_k_pairs_with_smallest_sums/Solution.java b/src.save/main/java/g0301_0400/s0373_find_k_pairs_with_smallest_sums/Solution.java
deleted file mode 100644
index c0ca7d8ba..000000000
--- a/src.save/main/java/g0301_0400/s0373_find_k_pairs_with_smallest_sums/Solution.java
+++ /dev/null
@@ -1,41 +0,0 @@
-package g0301_0400.s0373_find_k_pairs_with_smallest_sums;
-
-// #Medium #Array #Heap_Priority_Queue #2022_03_15_Time_58_ms_(29.29%)_Space_125_MB_(32.75%)
-
-import java.util.ArrayList;
-import java.util.List;
-import java.util.PriorityQueue;
-
-public class Solution {
- private static class Node {
- long sum;
- List al;
- int index;
-
- Node(int index, int num1, int num2) {
- this.sum = (long) num1 + (long) num2;
- this.al = new ArrayList<>();
- this.al.add(num1);
- this.al.add(num2);
- this.index = index;
- }
- }
-
- public List> kSmallestPairs(int[] nums1, int[] nums2, int k) {
- PriorityQueue queue = new PriorityQueue<>((a, b) -> a.sum < b.sum ? -1 : 1);
- List> res = new ArrayList<>();
- for (int i = 0; i < nums1.length && i < k; i++) {
- queue.add(new Node(0, nums1[i], nums2[0]));
- }
- for (int i = 1; i <= k && !queue.isEmpty(); i++) {
- Node cur = queue.poll();
- res.add(cur.al);
- int next = cur.index;
- int lastNum1 = cur.al.get(0);
- if (next + 1 < nums2.length) {
- queue.add(new Node(next + 1, lastNum1, nums2[next + 1]));
- }
- }
- return res;
- }
-}
diff --git a/src.save/main/java/g0301_0400/s0374_guess_number_higher_or_lower/Solution.java b/src.save/main/java/g0301_0400/s0374_guess_number_higher_or_lower/Solution.java
deleted file mode 100644
index 606188036..000000000
--- a/src.save/main/java/g0301_0400/s0374_guess_number_higher_or_lower/Solution.java
+++ /dev/null
@@ -1,33 +0,0 @@
-package g0301_0400.s0374_guess_number_higher_or_lower;
-
-// #Easy #Binary_Search #Interactive #2022_03_15_Time_0_ms_(100.00%)_Space_41_MB_(24.85%)
-
-/*
- * Forward declaration of guess API.
- *
- * @param num your guess
- * @return -1 if num is lower than the guess number 1 if num is higher than the guess number
- * otherwise return 0 int guess(int num);
- */
-public class Solution {
- public int guessNumber(int n) {
- int start = 0;
- int end = n;
- while (start <= end) {
- int mid = start + (end - start) / 2;
- if (guess(mid) == 0) {
- return mid;
- } else if (guess(mid) == -1) {
- end = mid - 1;
- } else {
- start = mid + 1;
- }
- }
- return -1;
- }
-
- // Assume we pick 7
- private int guess(int num) {
- return Integer.compare(7, num);
- }
-}
diff --git a/src.save/main/java/g0301_0400/s0375_guess_number_higher_or_lower_ii/Solution.java b/src.save/main/java/g0301_0400/s0375_guess_number_higher_or_lower_ii/Solution.java
deleted file mode 100644
index 4c1fdb14a..000000000
--- a/src.save/main/java/g0301_0400/s0375_guess_number_higher_or_lower_ii/Solution.java
+++ /dev/null
@@ -1,46 +0,0 @@
-package g0301_0400.s0375_guess_number_higher_or_lower_ii;
-
-// #Medium #Dynamic_Programming #Math #Game_Theory
-// #2022_03_16_Time_1_ms_(100.00%)_Space_41_MB_(78.48%)
-
-@SuppressWarnings("java:S135")
-public class Solution {
- int[][] matrix;
-
- public int getMoneyAmount(int n) {
- matrix = new int[n + 1][n + 1];
- return get(1, n);
- }
-
- private int get(int min, int max) {
- if (max - min < 3) {
- return max - min <= 0 ? 0 : max - 1;
- }
- if (matrix[min][max] != 0) {
- return matrix[min][max];
- }
- int select = max - 3;
- int minRes = Integer.MAX_VALUE;
- int res;
- int end = min + ((max - min) >> 1) - 1;
- int cnt = 0;
- while (true) {
- res = select + Math.max(get(min, select - 1), get(select + 1, max));
- if (res > minRes) {
- cnt++;
- if (cnt >= 3) {
- break;
- }
- }
- if (res < minRes) {
- minRes = res;
- }
- select--;
- if (select <= end) {
- break;
- }
- }
- matrix[min][max] = minRes;
- return minRes;
- }
-}
diff --git a/src.save/main/java/g0301_0400/s0376_wiggle_subsequence/Solution.java b/src.save/main/java/g0301_0400/s0376_wiggle_subsequence/Solution.java
deleted file mode 100644
index 95aed4f8e..000000000
--- a/src.save/main/java/g0301_0400/s0376_wiggle_subsequence/Solution.java
+++ /dev/null
@@ -1,19 +0,0 @@
-package g0301_0400.s0376_wiggle_subsequence;
-
-// #Medium #Array #Dynamic_Programming #Greedy #Dynamic_Programming_I_Day_18
-// #2022_03_16_Time_0_ms_(100.00%)_Space_41.9_MB_(29.05%)
-
-public class Solution {
- public int wiggleMaxLength(int[] nums) {
- int lt = 1;
- int gt = 1;
- for (int i = 1; i < nums.length; i++) {
- if (nums[i - 1] < nums[i]) {
- lt = gt + 1;
- } else if (nums[i - 1] > nums[i]) {
- gt = lt + 1;
- }
- }
- return Math.max(lt, gt);
- }
-}
diff --git a/src.save/main/java/g0301_0400/s0377_combination_sum_iv/Solution.java b/src.save/main/java/g0301_0400/s0377_combination_sum_iv/Solution.java
deleted file mode 100644
index bcbfd5715..000000000
--- a/src.save/main/java/g0301_0400/s0377_combination_sum_iv/Solution.java
+++ /dev/null
@@ -1,34 +0,0 @@
-package g0301_0400.s0377_combination_sum_iv;
-
-// #Medium #Array #Dynamic_Programming #Dynamic_Programming_I_Day_21
-// #2022_03_16_Time_1_ms_(91.72%)_Space_41.5_MB_(43.01%)
-
-import java.util.Arrays;
-
-public class Solution {
- int[] storage;
-
- public int combinationSum4(int[] nums, int target) {
- storage = new int[target + 1];
- Arrays.fill(storage, -1);
- return result(nums, target);
- }
-
- private int result(int[] nums, int target) {
- if (target < 0) {
- return 0;
- }
- if (target == 0) {
- return 1;
- }
- if (storage[target] != -1) {
- return storage[target];
- }
- int count = 0;
- for (int i : nums) {
- count += result(nums, target - i);
- }
- storage[target] = count;
- return count;
- }
-}
diff --git a/src.save/main/java/g0301_0400/s0378_kth_smallest_element_in_a_sorted_matrix/Solution.java b/src.save/main/java/g0301_0400/s0378_kth_smallest_element_in_a_sorted_matrix/Solution.java
deleted file mode 100644
index 5b29e981d..000000000
--- a/src.save/main/java/g0301_0400/s0378_kth_smallest_element_in_a_sorted_matrix/Solution.java
+++ /dev/null
@@ -1,53 +0,0 @@
-package g0301_0400.s0378_kth_smallest_element_in_a_sorted_matrix;
-
-// #Medium #Top_Interview_Questions #Array #Sorting #Binary_Search #Matrix #Heap_Priority_Queue
-// #2022_03_16_Time_0_ms_(100.00%)_Space_57.2_MB_(27.04%)
-
-public class Solution {
- public int kthSmallest(int[][] matrix, int k) {
- if (matrix == null || matrix.length == 0) {
- return -1;
- }
- int start = matrix[0][0];
- int end = matrix[matrix.length - 1][matrix[0].length - 1];
- // O(log(max-min)) time
- while (start + 1 < end) {
- int mid = start + (end - start) / 2;
- if (countLessEqual(matrix, mid) < k) {
- // look towards end
- start = mid;
- } else {
- // look towards start
- end = mid;
- }
- }
-
- // leave only with start and end, one of them must be the answer
- // try to see if start fits the criteria first
- if (countLessEqual(matrix, start) >= k) {
- return start;
- } else {
- return end;
- }
- }
-
- // countLessEqual
- // O(n) Time
- private int countLessEqual(int[][] matrix, int target) {
- // binary elimination from top right
- int row = 0;
- int col = matrix[0].length - 1;
- int count = 0;
- while (row < matrix.length && col >= 0) {
- if (matrix[row][col] <= target) {
- // get the count in current row
- count += col + 1;
- row++;
- } else if (matrix[row][col] > target) {
- // eliminate the current col
- col--;
- }
- }
- return count;
- }
-}
diff --git a/src.save/main/java/g0301_0400/s0382_linked_list_random_node/Solution.java b/src.save/main/java/g0301_0400/s0382_linked_list_random_node/Solution.java
deleted file mode 100644
index af7b61072..000000000
--- a/src.save/main/java/g0301_0400/s0382_linked_list_random_node/Solution.java
+++ /dev/null
@@ -1,35 +0,0 @@
-package g0301_0400.s0382_linked_list_random_node;
-
-// #Medium #Math #Linked_List #Randomized #Reservoir_Sampling
-// #2022_03_18_Time_7_ms_(100.00%)_Space_44.1_MB_(87.88%)
-
-import com_github_leetcode.ListNode;
-import java.util.ArrayList;
-import java.util.List;
-import java.util.Random;
-
-@SuppressWarnings("java:S2245")
-public class Solution {
- private List al;
- private Random rand;
-
- public Solution(ListNode head) {
- al = new ArrayList<>();
- rand = new Random();
- while (head != null) {
- al.add(head.val);
- head = head.next;
- }
- }
-
- public int getRandom() {
- /*
- Math.random() will generate a random number b/w 0 & 1.
- then multiply it with the array size.
- take only the integer part which is a random index.
- return the element at that random index.
- */
- int ind = rand.nextInt(al.size());
- return al.get(ind);
- }
-}
diff --git a/src.save/main/java/g0301_0400/s0383_ransom_note/Solution.java b/src.save/main/java/g0301_0400/s0383_ransom_note/Solution.java
deleted file mode 100644
index 794bda7e4..000000000
--- a/src.save/main/java/g0301_0400/s0383_ransom_note/Solution.java
+++ /dev/null
@@ -1,21 +0,0 @@
-package g0301_0400.s0383_ransom_note;
-
-// #Easy #String #Hash_Table #Counting #Data_Structure_I_Day_6_String
-// #2022_03_16_Time_1_ms_(99.79%)_Space_46.1_MB_(51.29%)
-
-public class Solution {
- public boolean canConstruct(String ransomNote, String magazine) {
- int[] a = new int[26];
- int n = ransomNote.length();
- for (int i = 0; i < n; i++) {
- a[ransomNote.charAt(i) - 97]++;
- }
- for (int i = 0; i < magazine.length() && n != 0; i++) {
- if (a[magazine.charAt(i) - 97] > 0) {
- n--;
- a[magazine.charAt(i) - 97]--;
- }
- }
- return n == 0;
- }
-}
diff --git a/src.save/main/java/g0301_0400/s0384_shuffle_an_array/Solution.java b/src.save/main/java/g0301_0400/s0384_shuffle_an_array/Solution.java
deleted file mode 100644
index 8852aa043..000000000
--- a/src.save/main/java/g0301_0400/s0384_shuffle_an_array/Solution.java
+++ /dev/null
@@ -1,38 +0,0 @@
-package g0301_0400.s0384_shuffle_an_array;
-
-// #Medium #Top_Interview_Questions #Array #Math #Randomized #Algorithm_II_Day_20_Others
-// #2022_03_18_Time_65_ms_(94.59%)_Space_50.3_MB_(91.27%)
-
-import java.util.Random;
-
-@SuppressWarnings("java:S2245")
-public class Solution {
- private int[] nums;
- private Random random;
-
- public Solution(int[] nums) {
- this.nums = nums;
- this.random = new Random();
- }
-
- // Resets the array to its original configuration and return it.
- public int[] reset() {
- return this.nums;
- }
-
- // Returns a random shuffling of the array.
- public int[] shuffle() {
- int[] shuffled = this.nums.clone();
- for (int i = nums.length - 1; i > 0; i--) {
- int j = random.nextInt(i + 1);
- swap(shuffled, i, j);
- }
- return shuffled;
- }
-
- private void swap(int[] shuffled, int i, int j) {
- int tmp = shuffled[i];
- shuffled[i] = shuffled[j];
- shuffled[j] = tmp;
- }
-}
diff --git a/src.save/main/java/g0301_0400/s0385_mini_parser/Solution.java b/src.save/main/java/g0301_0400/s0385_mini_parser/Solution.java
deleted file mode 100644
index 1b62c8b03..000000000
--- a/src.save/main/java/g0301_0400/s0385_mini_parser/Solution.java
+++ /dev/null
@@ -1,40 +0,0 @@
-package g0301_0400.s0385_mini_parser;
-
-// #Medium #String #Depth_First_Search #Stack #2022_03_16_Time_3_ms_(97.44%)_Space_44.6_MB_(60.81%)
-
-import com_github_leetcode.NestedInteger;
-
-public class Solution {
- private int i = 0;
-
- public NestedInteger deserialize(String s) {
- return getAns(s);
- }
-
- private NestedInteger getAns(String s) {
- if (s.charAt(i) == '[') {
- NestedInteger ni = new NestedInteger();
- i++;
- while (i < s.length() && s.charAt(i) != ']') {
- ni.add(getAns(s));
- }
- i++;
- return ni;
- } else if (s.charAt(i) == ',') {
- i++;
- return getAns(s);
- } else {
- int x = 0;
- int m = 1;
- if (s.charAt(i) == '-') {
- i++;
- m = -1;
- }
- while (i < s.length() && Character.isDigit(s.charAt(i))) {
- x = x * 10 + s.charAt(i++) - '0';
- }
- x *= m;
- return new NestedInteger(x);
- }
- }
-}
diff --git a/src.save/main/java/g0301_0400/s0386_lexicographical_numbers/Solution.java b/src.save/main/java/g0301_0400/s0386_lexicographical_numbers/Solution.java
deleted file mode 100644
index 13e3cb207..000000000
--- a/src.save/main/java/g0301_0400/s0386_lexicographical_numbers/Solution.java
+++ /dev/null
@@ -1,30 +0,0 @@
-package g0301_0400.s0386_lexicographical_numbers;
-
-// #Medium #Depth_First_Search #Trie #2022_03_16_Time_4_ms_(87.17%)_Space_56.9_MB_(38.24%)
-
-import java.util.ArrayList;
-import java.util.List;
-
-public class Solution {
- public List lexicalOrder(int n) {
- List lst = new ArrayList<>();
- dfs(lst, n, 0);
- return lst;
- }
-
- private void dfs(List lst, int n, int num) {
- for (int i = 0; i <= 9; i++) {
- int cur = 10 * num + i;
- // get rid of 0
- if (cur == 0) {
- continue;
- }
- // when larger than n, return to the previous level
- if (cur > n) {
- return;
- }
- lst.add(cur);
- dfs(lst, n, cur);
- }
- }
-}
diff --git a/src.save/main/java/g0301_0400/s0387_first_unique_character_in_a_string/Solution.java b/src.save/main/java/g0301_0400/s0387_first_unique_character_in_a_string/Solution.java
deleted file mode 100644
index d9e32cffd..000000000
--- a/src.save/main/java/g0301_0400/s0387_first_unique_character_in_a_string/Solution.java
+++ /dev/null
@@ -1,20 +0,0 @@
-package g0301_0400.s0387_first_unique_character_in_a_string;
-
-// #Easy #Top_Interview_Questions #String #Hash_Table #Counting #Queue
-// #Data_Structure_I_Day_6_String #2022_03_16_Time_2_ms_(99.53%)_Space_48.4_MB_(64.14%)
-
-public class Solution {
- public int firstUniqChar(String s) {
- int ans = Integer.MAX_VALUE;
- for (char i = 'a'; i <= 'z'; i++) {
- int ind = s.indexOf(i);
- if (ind != -1 && ind == s.lastIndexOf(i)) {
- ans = Math.min(ans, ind);
- }
- }
- if (ans == Integer.MAX_VALUE) {
- return -1;
- }
- return ans;
- }
-}
diff --git a/src.save/main/java/g0301_0400/s0388_longest_absolute_file_path/Solution.java b/src.save/main/java/g0301_0400/s0388_longest_absolute_file_path/Solution.java
deleted file mode 100644
index 32953da2a..000000000
--- a/src.save/main/java/g0301_0400/s0388_longest_absolute_file_path/Solution.java
+++ /dev/null
@@ -1,70 +0,0 @@
-package g0301_0400.s0388_longest_absolute_file_path;
-
-// #Medium #String #Depth_First_Search #Stack #2022_03_16_Time_2_ms_(52.22%)_Space_42.5_MB_(14.38%)
-
-import java.util.ArrayDeque;
-import java.util.Deque;
-
-public class Solution {
- public int lengthLongestPath(String input) {
- Deque stack = new ArrayDeque<>();
- int longestLen = 0;
- int currDirLen = 0;
- int i = 0;
- int currLevel = 0;
- int nextLevel = 0;
- boolean isFile = false;
- Character period = '.';
- Character space = ' ';
- while (i < input.length()) {
- currLevel = nextLevel;
- int currStrLen = 0;
- while (i < input.length()
- && (Character.isLetterOrDigit(input.charAt(i))
- || period.equals(input.charAt(i))
- || space.equals(input.charAt(i)))) {
- if (period.equals(input.charAt(i))) {
- isFile = true;
- }
- i++;
- currStrLen++;
- }
- if (isFile) {
- longestLen = Math.max(longestLen, currDirLen + currStrLen);
- } else {
- currDirLen += currStrLen + 1;
- stack.push(currStrLen + 1);
- }
- nextLevel = 0;
- // increment one to let it pass "\n" and start from "\t"
- i = i + 1;
- while (i < input.length() - 1 && input.charAt(i) == '\t') {
- nextLevel++;
- i = i + 1;
- }
- if (nextLevel < currLevel) {
- int j = 0;
- if (isFile) {
- while (!stack.isEmpty() && j < (currLevel - nextLevel)) {
- currDirLen -= stack.pop();
- j++;
- }
- } else {
- while (!stack.isEmpty() && j <= (currLevel - nextLevel)) {
- currDirLen -= stack.pop();
- j++;
- }
- }
- } else if (nextLevel == currLevel && !isFile && !stack.isEmpty()) {
- currDirLen -= stack.pop();
- }
- if (nextLevel == 0) {
- currDirLen = 0;
- stack.clear();
- }
- isFile = false;
- }
-
- return longestLen;
- }
-}
diff --git a/src.save/main/java/g0301_0400/s0389_find_the_difference/Solution.java b/src.save/main/java/g0301_0400/s0389_find_the_difference/Solution.java
deleted file mode 100644
index 1eca9d4e8..000000000
--- a/src.save/main/java/g0301_0400/s0389_find_the_difference/Solution.java
+++ /dev/null
@@ -1,17 +0,0 @@
-package g0301_0400.s0389_find_the_difference;
-
-// #Easy #String #Hash_Table #Sorting #Bit_Manipulation #Programming_Skills_I_Day_8_String
-// #2022_03_16_Time_1_ms_(99.83%)_Space_40.3_MB_(90.11%)
-
-public class Solution {
- public char findTheDifference(String s, String t) {
- char c = 0;
- for (char cs : s.toCharArray()) {
- c ^= cs;
- }
- for (char ct : t.toCharArray()) {
- c ^= ct;
- }
- return c;
- }
-}
diff --git a/src.save/main/java/g0301_0400/s0390_elimination_game/Solution.java b/src.save/main/java/g0301_0400/s0390_elimination_game/Solution.java
deleted file mode 100644
index 349900cb7..000000000
--- a/src.save/main/java/g0301_0400/s0390_elimination_game/Solution.java
+++ /dev/null
@@ -1,9 +0,0 @@
-package g0301_0400.s0390_elimination_game;
-
-// #Medium #Math #2022_03_16_Time_2_ms_(100.00%)_Space_41.3_MB_(71.55%)
-
-public class Solution {
- public int lastRemaining(int n) {
- return n == 1 ? 1 : 2 * (n / 2 - lastRemaining(n / 2) + 1);
- }
-}
diff --git a/src.save/main/java/g0301_0400/s0391_perfect_rectangle/Solution.java b/src.save/main/java/g0301_0400/s0391_perfect_rectangle/Solution.java
deleted file mode 100644
index 332657f65..000000000
--- a/src.save/main/java/g0301_0400/s0391_perfect_rectangle/Solution.java
+++ /dev/null
@@ -1,88 +0,0 @@
-package g0301_0400.s0391_perfect_rectangle;
-
-// #Hard #Array #Line_Sweep #2022_03_16_Time_49_ms_(67.32%)_Space_64.9_MB_(22.57%)
-
-import java.util.HashSet;
-import java.util.Objects;
-import java.util.Set;
-
-public class Solution {
- public boolean isRectangleCover(int[][] rectangles) {
- Set container = new HashSet<>();
- // add each rectangle area to totalArea
- int totalArea = 0;
- // A rectangle has four points, if a point appears twice, it will be deleted it from the set
- for (int[] rectangle : rectangles) {
- totalArea += (rectangle[2] - rectangle[0]) * (rectangle[3] - rectangle[1]);
- Point p1 = new Point(rectangle[0], rectangle[1]);
- Point p2 = new Point(rectangle[2], rectangle[1]);
- Point p3 = new Point(rectangle[2], rectangle[3]);
- Point p4 = new Point(rectangle[0], rectangle[3]);
- if (container.contains(p1)) {
- container.remove(p1);
- } else {
- container.add(p1);
- }
- if (container.contains(p2)) {
- container.remove(p2);
- } else {
- container.add(p2);
- }
- if (container.contains(p3)) {
- container.remove(p3);
- } else {
- container.add(p3);
- }
- if (container.contains(p4)) {
- container.remove(p4);
- } else {
- container.add(p4);
- }
- }
- // A perfect rectangle must has four points
- if (container.size() != 4) {
- return false;
- }
-
- // these four points represent the last perfect rectangle, check this rectangle area to the
- // totalArea
- int minX = Integer.MAX_VALUE;
- int maxX = Integer.MIN_VALUE;
- int minY = Integer.MAX_VALUE;
- int maxY = Integer.MIN_VALUE;
- for (Point p : container) {
- minX = Math.min(minX, p.x);
- maxX = Math.max(maxX, p.x);
- minY = Math.min(minY, p.y);
- maxY = Math.max(maxY, p.y);
- }
- return totalArea == (maxX - minX) * (maxY - minY);
- }
-
- private static class Point {
- private final int x;
- private final int y;
-
- public Point(int x, int y) {
- this.x = x;
- this.y = y;
- }
-
- @Override
- public boolean equals(Object o) {
- if (this == o) {
- return true;
- }
- if (o == null || getClass() != o.getClass()) {
- return false;
- }
- Point point = (Point) o;
- return x == point.x && y == point.y;
- }
-
- @Override
- public int hashCode() {
- return Objects.hash(x, y);
- }
- }
-}
diff --git a/src.save/main/java/g0301_0400/s0392_is_subsequence/Solution.java b/src.save/main/java/g0301_0400/s0392_is_subsequence/Solution.java
deleted file mode 100644
index 0ba4455cd..000000000
--- a/src.save/main/java/g0301_0400/s0392_is_subsequence/Solution.java
+++ /dev/null
@@ -1,26 +0,0 @@
-package g0301_0400.s0392_is_subsequence;
-
-// #Easy #String #Dynamic_Programming #Two_Pointers #Dynamic_Programming_I_Day_19
-// #2022_03_16_Time_0_ms_(100.00%)_Space_42.2_MB_(40.05%)
-
-public class Solution {
- public boolean isSubsequence(String s, String t) {
- int i = 0;
- int j = 0;
- int n = t.length();
- int m = s.length();
- if (m == 0) {
- return true;
- }
- while (j < n) {
- if (s.charAt(i) == t.charAt(j)) {
- i++;
- if (i == m) {
- return true;
- }
- }
- j++;
- }
- return false;
- }
-}
diff --git a/src.save/main/java/g0301_0400/s0393_utf_8_validation/Solution.java b/src.save/main/java/g0301_0400/s0393_utf_8_validation/Solution.java
deleted file mode 100644
index 6266977ca..000000000
--- a/src.save/main/java/g0301_0400/s0393_utf_8_validation/Solution.java
+++ /dev/null
@@ -1,29 +0,0 @@
-package g0301_0400.s0393_utf_8_validation;
-
-// #Medium #Array #Bit_Manipulation #2022_03_16_Time_1_ms_(100.00%)_Space_47_MB_(66.67%)
-
-public class Solution {
- public boolean validUtf8(int[] data) {
- int count = 0;
- for (int d : data) {
- if (count == 0) {
- if (d >> 5 == 0b110) {
- count = 1;
- } else if (d >> 4 == 0b1110) {
- count = 2;
- } else if (d >> 3 == 0b11110) {
- count = 3;
- } else if (d >> 7 == 1) {
- return false;
- }
- } else {
- if (d >> 6 != 0b10) {
- return false;
- } else {
- count--;
- }
- }
- }
- return count == 0;
- }
-}
diff --git a/src.save/main/java/g0301_0400/s0394_decode_string/Solution.java b/src.save/main/java/g0301_0400/s0394_decode_string/Solution.java
deleted file mode 100644
index 21df1b39c..000000000
--- a/src.save/main/java/g0301_0400/s0394_decode_string/Solution.java
+++ /dev/null
@@ -1,32 +0,0 @@
-package g0301_0400.s0394_decode_string;
-
-// #Medium #Top_100_Liked_Questions #String #Stack #Recursion
-// #2022_03_16_Time_1_ms_(83.81%)_Space_42.1_MB_(38.87%)
-
-public class Solution {
- private int i = 0;
-
- public String decodeString(String s) {
- int count = 0;
- StringBuilder sb = new StringBuilder();
- while (i < s.length()) {
- char c = s.charAt(i);
- i++;
- if (Character.isLetter(c)) {
- sb.append(c);
- } else if (Character.isDigit(c)) {
- count = count * 10 + Character.getNumericValue(c);
- } else if (c == ']') {
- break;
- } else if (c == '[') {
- // sub problem
- String repeat = decodeString(s);
- while (count > 0) {
- sb.append(repeat);
- count--;
- }
- }
- }
- return sb.toString();
- }
-}
diff --git a/src.save/main/java/g0301_0400/s0395_longest_substring_with_at_least_k_repeating_characters/Solution.java b/src.save/main/java/g0301_0400/s0395_longest_substring_with_at_least_k_repeating_characters/Solution.java
deleted file mode 100644
index b99246b0b..000000000
--- a/src.save/main/java/g0301_0400/s0395_longest_substring_with_at_least_k_repeating_characters/Solution.java
+++ /dev/null
@@ -1,31 +0,0 @@
-package g0301_0400.s0395_longest_substring_with_at_least_k_repeating_characters;
-
-// #Medium #Top_Interview_Questions #String #Hash_Table #Sliding_Window #Divide_and_Conquer
-// #2022_03_16_Time_0_ms_(100.00%)_Space_41.9_MB_(62.59%)
-
-public class Solution {
- public int longestSubstring(String s, int k) {
- return helper(s, k, 0, s.length());
- }
-
- private int helper(String s, int k, int start, int end) {
- if (end - start < k) {
- return 0;
- }
- int[] nums = new int[26];
- for (int i = start; i < end; i++) {
- nums[s.charAt(i) - 'a']++;
- }
-
- for (int i = start; i < end; i++) {
- if (nums[s.charAt(i) - 'a'] < k) {
- int j = i + 1;
- while (j < s.length() && nums[s.charAt(j) - 'a'] < k) {
- j++;
- }
- return Math.max(helper(s, k, start, i), helper(s, k, j, end));
- }
- }
- return end - start;
- }
-}
diff --git a/src.save/main/java/g0301_0400/s0396_rotate_function/Solution.java b/src.save/main/java/g0301_0400/s0396_rotate_function/Solution.java
deleted file mode 100644
index e68c88c10..000000000
--- a/src.save/main/java/g0301_0400/s0396_rotate_function/Solution.java
+++ /dev/null
@@ -1,21 +0,0 @@
-package g0301_0400.s0396_rotate_function;
-
-// #Medium #Dynamic_Programming #Math #2022_03_16_Time_3_ms_(98.51%)_Space_54.4_MB_(90.05%)
-
-public class Solution {
- public int maxRotateFunction(int[] nums) {
- int allSum = 0;
- int len = nums.length;
- int f = 0;
- for (int i = 0; i < len; i++) {
- f += i * nums[i];
- allSum += nums[i];
- }
- int max = f;
- for (int i = len - 1; i >= 1; i--) {
- f = f + allSum - len * nums[i];
- max = Math.max(f, max);
- }
- return max;
- }
-}
diff --git a/src.save/main/java/g0301_0400/s0397_integer_replacement/Solution.java b/src.save/main/java/g0301_0400/s0397_integer_replacement/Solution.java
deleted file mode 100644
index 7aac079eb..000000000
--- a/src.save/main/java/g0301_0400/s0397_integer_replacement/Solution.java
+++ /dev/null
@@ -1,31 +0,0 @@
-package g0301_0400.s0397_integer_replacement;
-
-// #Medium #Dynamic_Programming #Greedy #Bit_Manipulation #Memoization
-// #2022_03_16_Time_0_ms_(100.00%)_Space_39.3_MB_(62.74%)
-
-import java.util.HashMap;
-import java.util.Map;
-
-public class Solution {
- public int integerReplacement(int n) {
- Map