NeverCry's Solutions

Last Update: 9/16/2025, 5:39:46 AM

Solutions

Problem	Difficulty	Tags	Solution
1. Two Sum 🔗	Easy	Array, Hash Table	cpp
3. Longest Substring Without Repeating Characters 🔗	Medium	Hash Table, String, Sliding Window	python3
5. Longest Palindromic Substring 🔗	Medium	Two Pointers, String, Dynamic Programming	python3
11. Container With Most Water 🔗	Medium	Array, Two Pointers, Greedy	cpp
15. 3Sum 🔗	Medium	Array, Two Pointers, Sorting	cpp | python3
20. Valid Parentheses 🔗	Easy	String, Stack	python3
21. Merge Two Sorted Lists 🔗	Easy	Linked List, Recursion	python3
23. Merge k Sorted Lists 🔗	Hard	Linked List, Divide and Conquer, Heap (Priority Queue), Merge Sort	python3
39. Combination Sum 🔗	Medium	Array, Backtracking	python3
49. Group Anagrams 🔗	Medium	Array, Hash Table, String, Sorting	cpp | python
50. Pow(x, n) 🔗	Medium	Math, Recursion	python3
70. Climbing Stairs 🔗	Easy	Math, Dynamic Programming, Memoization	python3
74. Search a 2D Matrix 🔗	Medium	Array, Binary Search, Matrix	cpp
78. Subsets 🔗	Medium	Array, Backtracking, Bit Manipulation	python3
79. Word Search 🔗	Medium	Array, String, Backtracking, Depth-First Search, Matrix	python3
112. Path Sum 🔗	Easy	Tree, Depth-First Search, Breadth-First Search, Binary Tree	python3
121. Best Time to Buy and Sell Stock 🔗	Easy	Array, Dynamic Programming	python3
125. Valid Palindrome 🔗	Easy	Two Pointers, String	python3
128. Longest Consecutive Sequence 🔗	Medium	Array, Hash Table, Union Find	python3
133. Clone Graph 🔗	Medium	Hash Table, Depth-First Search, Breadth-First Search, Graph	cpp
139. Word Break 🔗	Medium	Array, Hash Table, String, Dynamic Programming, Trie, Memoization	python3
167. Two Sum II - Input Array Is Sorted 🔗	Medium	Array, Two Pointers, Binary Search	python3
200. Number of Islands 🔗	Medium	Array, Depth-First Search, Breadth-First Search, Union Find, Matrix	cpp
208. Implement Trie (Prefix Tree) 🔗	Medium	Hash Table, String, Design, Trie	python3
209. Minimum Size Subarray Sum 🔗	Medium	Array, Binary Search, Sliding Window, Prefix Sum	python3
217. Contains Duplicate 🔗	Easy	Array, Hash Table, Sorting	python3
219. Contains Duplicate II 🔗	Easy	Array, Hash Table, Sliding Window	python3
226. Invert Binary Tree 🔗	Easy	Tree, Depth-First Search, Breadth-First Search, Binary Tree	python3
230. Kth Smallest Element in a BST 🔗	Medium	Tree, Depth-First Search, Binary Search Tree, Binary Tree	python3
238. Product of Array Except Self 🔗	Medium	Array, Prefix Sum	python3
242. Valid Anagram 🔗	Easy	Hash Table, String, Sorting	python
268. Missing Number 🔗	Easy	Array, Hash Table, Math, Binary Search, Bit Manipulation, Sorting	python3
303. Range Sum Query - Immutable 🔗	Easy	Array, Design, Prefix Sum	python3
332. Reconstruct Itinerary 🔗	Hard	Depth-First Search, Graph, Eulerian Circuit	cpp | java
341. Flatten Nested List Iterator 🔗	Medium	Stack, Tree, Depth-First Search, Design, Queue, Iterator	cpp
344. Reverse String 🔗	Easy	Two Pointers, String	cpp | python3
347. Top K Frequent Elements 🔗	Medium	Array, Hash Table, Divide and Conquer, Sorting, Heap (Priority Queue), Bucket Sort, Counting, Quickselect	python3
417. Pacific Atlantic Water Flow 🔗	Medium	Array, Depth-First Search, Breadth-First Search, Matrix	cpp
424. Longest Repeating Character Replacement 🔗	Medium	Hash Table, String, Sliding Window	python3
456. 132 Pattern 🔗	Medium	Array, Binary Search, Stack, Monotonic Stack, Ordered Set	cpp
463. Island Perimeter 🔗	Easy	Array, Depth-First Search, Breadth-First Search, Matrix	cpp
547. Number of Provinces 🔗	Medium	Depth-First Search, Breadth-First Search, Union Find, Graph	cpp
561. Array Partition 🔗	Easy	Array, Greedy, Sorting, Counting Sort	python3
567. Permutation in String 🔗	Medium	Hash Table, Two Pointers, String, Sliding Window	python3
695. Max Area of Island 🔗	Medium	Array, Depth-First Search, Breadth-First Search, Union Find, Matrix	cpp
724. Find Pivot Index 🔗	Easy	Array, Prefix Sum	cpp
739. Daily Temperatures 🔗	Medium	Array, Stack, Monotonic Stack	python3
743. Network Delay Time 🔗	Medium	Depth-First Search, Breadth-First Search, Graph, Heap (Priority Queue), Shortest Path	cpp
797. All Paths From Source to Target 🔗	Medium	Backtracking, Depth-First Search, Breadth-First Search, Graph	cpp
853. Car Fleet 🔗	Medium	Array, Stack, Sorting, Monotonic Stack	python3
874. Walking Robot Simulation 🔗	Medium	Array, Hash Table, Simulation	cpp
875. Koko Eating Bananas 🔗	Medium	Array, Binary Search	python3 | python
994. Rotting Oranges 🔗	Medium	Array, Breadth-First Search, Matrix	cpp | python3
1091. Shortest Path in Binary Matrix 🔗	Medium	Array, Breadth-First Search, Matrix	cpp
1343. Number of Sub-arrays of Size K and Average Greater than or Equal to Threshold 🔗	Medium	Array, Sliding Window	python3
1491. Average Salary Excluding the Minimum and Maximum Salary 🔗	Easy	Array, Sorting	cpp
1514. Path with Maximum Probability 🔗	Medium	Array, Graph, Heap (Priority Queue), Shortest Path	cpp
1550. Three Consecutive Odds 🔗	Easy	Array	python3
1971. Find if Path Exists in Graph 🔗	Easy	Depth-First Search, Breadth-First Search, Union Find, Graph	cpp