td

lungzeeyim · lungzeeyim · commit 45ea5a316f84 · 2017-08-01T12:03:34.000-04:00
diff --git a/4/PostOrder.class b/4/PostOrder.class
diff --git a/4/PostOrder.java b/4/PostOrder.java
@@ -0,0 +1,61 @@
+import java.util.*;
+
+public class PostOrder {
+    public List<Integer> postOrder1(TreeNode root) {
+        List<Integer> result = new ArrayList<Integer>();
+        if (root == null) {
+            return result;
+        }
+        Deque<TreeNode> dque = new LinkedList<TreeNode>();
+        dque.offerFirst(root);
+        while (!dque.isEmpty()) {
+            TreeNode cur = dque.pollFirst();
+            result.add(cur.key);
+            if (cur.left != null) {
+                dque.offerFirst(cur.left);
+            }
+            if (cur.right != null) {
+                dque.offerFirst(cur.right);
+            }
+        }
+        Collections.reverse(result);
+        return result;
+    }
+    public static void main(String[] arsgs) {
+        TreeNode tn1 = new TreeNode(5);
+        TreeNode tn2 = new TreeNode(3);
+        TreeNode tn3 = new TreeNode(8);
+        TreeNode tn4 = new TreeNode(1);
+        TreeNode tn5 = new TreeNode(4);
+        TreeNode tn6 = new TreeNode(11);
+
+        tn1.left = tn2;
+        tn1.right = tn3;
+        tn2.left = tn4;
+        tn2.right = tn5;
+        tn3.right = tn6;
+
+        PostOrder po = new PostOrder();
+        List<Integer> list = po.postOrder1(tn1);
+        System.out.println(list.toString());
+
+
+    }
+}
+
+/* 
+        5
+
+      /    \
+
+    3        8
+
+  /   \        \
+
+1      4        11
+
+Post-order traversal is [1, 4, 3, 11, 8, 5]
+
+
+
+*/
diff --git a/4/PostOrder.java~ b/4/PostOrder.java~
@@ -0,0 +1,5 @@
+public class PostOrder {
+
+
+
+}
diff --git a/7/#RemoveSpace.java# b/7/#RemoveSpace.java#
@@ -0,0 +1,56 @@
+public class RemoveSpace {
+    public String removeSpace(String input) {
+        if (input.isEmpty()) {                                       // check empty, empty -> return 
+            return input;
+        }
+        char[] array = input.toCharArray();                          // String to Char array
+        int end = 0;                                                 // end = 0
+        for (int i = 0; i < array.length; i++) {                     // loop array.length times
+            if (array[i] == ' ' && (i == 0 || array[i-1] == ' ')) {  // 
+                continue;
+            }
+            array[end++] = array[i];
+        }
+        if (end > 0 && array[end - 1] == ' ') {
+            return new String(array, 0, end - 1);
+        }        
+        return new String(array, 0, end);
+    }
+
+    public static void main(String[] args) {
+        RemoveSpace rm = new RemoveSpace();
+        System.out.println(rm.removeSpace("  I     love MTV "));
+    }
+}
+
+
+/*
+string = " I love  MTV "
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+ */
+
+
+
+
+
+
+
+
+
+
+
diff --git a/7/RemoveSpace.class b/7/RemoveSpace.class
diff --git a/7/RemoveSpace.java b/7/RemoveSpace.java
@@ -0,0 +1,56 @@
+public class RemoveSpace {
+    public String removeSpace(String input) {
+        if (input.isEmpty()) {
+            return input;
+        }
+        char[] array = input.toCharArray();
+        int end = 0;
+        for (int i = 0; i < array.length; i++) {
+            if (array[i] == ' ' && (i == 0 || array[i-1] == ' ')) {
+                continue;
+            }
+            array[end++] = array[i];
+        }
+        if (end > 0 && array[end - 1] == ' ') {
+            return new String(array, 0, end - 1);
+        }        
+        return new String(array, 0, end);
+    }
+
+    public static void main(String[] args) {
+        RemoveSpace rm = new RemoveSpace();
+        System.out.println(rm.removeSpace("  I     love MTV "));
+    }
+}
+
+
+/*
+string = " I love  MTV "
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+ */
+
+
+
+
+
+
+
+
+
+
+
diff --git a/7/RemoveSpace.java~ b/7/RemoveSpace.java~
@@ -0,0 +1,20 @@
+public class RemoveSpace {
+    public String removeSpace(String input) {
+        if (input.isEmpty()) {
+            return input;
+        }
+        char[] array = input.toCharArray();
+        int end = 0;
+        for (int i = 0; i < array.length; i++) {
+            if (array[i] == ' ' && (i == 0 || array[i-1] == ' ')) {
+                continue;
+            }
+            if (end > 0 && array[end - 1] == ' ') {
+                return new String(array, 0, end - 1)
+                    
+            }
+            return new String(array, 0, end);
+        }
+    }
+
+}
diff --git a/8/Permutation.class b/8/Permutation.class
diff --git a/8/Permutation.java b/8/Permutation.java
@@ -0,0 +1,40 @@
+import java.util.*;
+
+public class Permutation {
+    
+	public List<String> permutation(String set) {
+        List<String> result = new ArrayList<String>();
+        if (set == null) return result;
+        char[] array = set.toCharArray();
+        helper(array, 0, result);
+        return result;
+    }
+
+    private void helper(char[] array, int index, List<String> result) {
+        if (index == array.length) {
+            result.add(new String(array));
+            return;
+        }
+        Set<Character> used = new HashSet<Character>();
+        for (int i = index; i < array.length; i++) {
+            if (used.add(array[i])) {
+                swap(array, i, index);
+                helper(array, index + 1, result);
+                swap(array, i, index);
+            }
+        }
+    }
+
+    private void swap(char[] array, int left, int right) {
+        char temp = array[left];
+        array[left] = array[right];
+        array[right] = temp;
+    }
+    
+    public static void main(String[] args) {
+        Permutation per = new Permutation();
+        List<String> result;
+        result = per.permutation("ab");
+        System.out.println(result.toString());
+    }
+}
diff --git a/8/Permutation.java~ b/8/Permutation.java~
@@ -0,0 +1,12 @@
+public class Permutation() {
+	public List<String> permutation(String set) {
+		
+    }
+
+    public static void main(String[] args) {
+        Permutation per = new Permutation();
+        List<String> result;
+        result = per.permutation("ab");
+        System.out.println(result.toString());
+    }
+}

-Original file line number
+Diff line change
@@ @@ -0,0 +1,5 @@ @@
 +public class PostOrder {
++
++
++
 +}