LeetCode Solutions
| problems | tags(Data Structure & Algorithm) | Solution | Comments |
|---|---|---|---|
| 1. TwoSum | Array & Hash Table | Done | Easy |
| 2. Add Two Numbers | Linked List | Done | Medium |
| 3. Longest Substring Without Repeating Characters | Strings & Hash Table & Sliding Window | Done | Medium |
| 18. 4Sum | Array & Hash Table && Two Pointers | Done | Medium |
| 23. Merge k Sorted Lists | Linked List & Divde and Conquer & Heap | Done | Hard |
| 42. Trapping Rain Water | Array & Two Pointers & Stack | Done | Hard |
| 45. Jump Game II | Array & Greedy | Done | Hard |
| 49. Group Anagrams | Hash Table & String | Done | Medium |
| 53. Maximum Subarray | Array & Dynamic Programming | Done | Easy |
| 55. Jump Game | Array & Greddy | Done | Medium |
| 70. Climbing Stairs | Dynamic Programming | Done | Easy |
| 76. Minimum Window Substring | Hash Table && Two Pointers & String & Sliding Window | TODO | Hard |
| 82. Remove Duplicates from Sorted List ii | Linked List | Done | Medium |
| 84. Largest Rectangle in Histogram | Array & Stack | Done | Hard |
| 85. Maximal Rectangle | Array & Hash Table & Dynamic Programming & Stack | Done | Hard |
| 91. Decode Ways | String & Dynamic Programming | Done | Medium |
| 94. Binary Tree Inorder Traversal | Hash Table & Stack & Tree | Done | Medium |
| 95. Unique Binary Search Trees ii | Dynamic Programming & Tree | Done | Medium |
| 96. Unique Binary Search Trees | Dynamic Programming & Tree | Done | Medium |
| 98. Validate Binary Search Tree | Tree & Depth Frist Search | Done | Medium |
| 99. Recover Binary Search Tree | Tree & Depth Frist Search | Done | Hard |
| 100. Same Tree | Tree & Depth-First-Search | Done | Easy |
| 102. Binary Tree Level Order Traversal | Tree & Breath-First-Search | Done | Medium |
| 103. Binary Tree Zigzag Level Order Traversal | Stack & Tree & Breath-First-Search | Done | Medium |
| 105. Construct Binary Tree from Preorder and Inorder Traversal | Array & Tree & Depth-First-Search | Done | Medium |
| 106. Construct Binary Tree from Inorder and Postorder Traversal | Array & Tree & Depth-First-Search | Done | Medium |
| 113. Path Sum II | Tree & Depth-First-Search | Done | Medium |
| 114. Flatten Binary Tree to Linked List | Tree & Depth-First-Search | TODO | Medium |
| 120. Triangle | Array & Dynamic Programming | Done | Medium |
| 127. Word Ladder | Breath First Search | Done | Medium |
| 129. Sum Root to Leaf Numbers | Tree & Depth First Search | Done | Medium |
| 134. Gas Station | Greedy | Done | Medium |
| 135. Candy | Greedy | Done | Hard |
| 136. Single Number | Hash Table & Bit Manipulation | Done | Easy |
| 139. Word Break | Dynamic Programming | Done | Medium |
| 144. Binary Tree Preorder Traversal | Stack & Tree | Done | Medium |
| 145. Binary Tree Postorder Traversal | Stack & Tree | Done | Medium |
| 152. Maximum Product Subarray | Array & Dynamic Programming | Done | Medium |
| 167. Two Sum II - Input array is sorted | Array & Two Pointer | Done | Easy |
| 191. Number of 1 Bits | Bit Manipulation | Done | Easy |
| 198. House Robber | Dynamic Programming | Done | Easy |
| 199. Binary Tree Right Side Views | Tree & Depth First Search & Breath First Search | Done | Medium |
| 207. Course Schedule | Depth First Search & Breath First Search & Graph & Topological Sort | Done | Medium |
| 213. House Robber II | Dynamic Programming | Done | Medium |
| 221. Maximal Square | Dynamic Programming | Done | Medium |
| 222. Count Complete Tree Nodes | Binary Search & Tree | Done | Medium |
| 240. Search a 2D Matrix II | Binary Search & Divide and Conquer | Done | Medium |
| 241. Different Ways to Add Parentheses | Divide and Conquer | Done | Medium |
| 264. Ugly Number II | Dynamic Programming | Done | Medium |
| 279. Perfect Squares | Dynamic Programming & Breadth Frist Search | Done | Medium |
| 289. Game of Life | Array | Done | Medium |
| 303. Range Sum Query - Immutable | Array | Done | Easy |
| 312. Burst Balloons | Divide and Conquer & Dynamic Programming | Done | Hard |
| 315. Count of Smaller Numbers After Self | Binary Search & Divide and Conquer & Sort & Binary Indexed Tree & Segment Tree | Done | Medium |
| 316. Remove Duplicate Letters | Stack & Greedy | Done | Hard |
| 327. Count of Range Sum | Binary Search & Divide and Conquer & Sort & Binary Indexed Tree & Segment Tree | Done | Hard |
| 343. Integer Break | Dynamic Programming | Done | Medium |
| 347. Top K Frequent Elements | Hash Table & Heap | Done | Medium |
| 371. Sum of Two Integers | Bit Manipulation | Done | Medium |
| 409. Longest Palindrome | Hash Table | Done | Easy |
| 455. Assign Cookies | Greedy | Done | Easy |
| 559. Maximum Depth of N-ary Tree | Depth-First Search & Breadth-First Search & Tree | Done | Easy |
| 621. Task Scheduler | Array & Greedy & Queue | Done | Medium |
| 690. Employee Importance | Hash Table & Depth-First Search & Breadth-First Search | Done | Easy |
| 787. Cheapest Flights Within K Stops | Dynamic Programming & Heap & Breadth-First Search | Done | Medium |
| 860. Lemonade Change | Greedy | Done | Easy |
| 932. Beautiful Array | Divide and Conquer | Done | Medium |