- 数组 - Array
| No | Title | Solution | Difficulty |
|---|---|---|---|
| 1 | Two Sum | Java | Easy |
| 3 | Longest Substring Without Repeating Characters | Java | Medium |
| 26 | Remove Duplicates from Sorted Array | Java | Easy |
| 27 | Remove Element | Java | Easy |
| 75 | Sort Colors | Java | Medium |
| 76 | Minimum Window Substring | Java | Hard |
| 80 | Remove Duplicates from Sorted Array II | Java | Medium |
| 167 | Two Sum II - Input array is sorted | Java | Easy |
| 209 | Minimum Size Subarray Sum | Java | Medium |
| 215 | Kth Largest Element in an Array | Java | Medium |
| 283 | Move Zeroes | Java | Easy |
- 链表 - LinkedList
| No | Title | Solution | Difficulty |
|---|---|---|---|
| 2 | Swap Nodes in Pairs | Java | Medium |
| 19 | Remove Nth Node From End of List | Java | Medium |
| 24 | Add Two Numbers | Java | Medium |
| 61 | Rotate List | Java | Medium |
| 83 | Remove Duplicates from Sorted List | Java | Easy |
| 92 | Reverse Linked List II | Java | Medium |
| 143 | Reorder List | Java | Easy |
| 203 | Remove Linked List Elements | Java | Easy |
| 445 | Add Two Numbers II | Java | Medium |
- 栈 - Stack
| No | Title | Solution | Difficulty |
|---|---|---|---|
| 20 | Valid Parentheses | Java | Easy |
| 71 | Simplify Path | Java | Medium |
| 150 | Evaluate Reverse Polish Notation | Java | Medium |
| 341 | Flatten Nested List Iterator | Java | Medium |
- 优先队列 - PriorityQueue
| No | Title | Solution | Difficulty |
|---|---|---|---|
| 23 | Merge k Sorted Lists | Java | Hard |
| 347 | Top K Frequent Elements | Java | Medium |
- 二叉树 - Tree
| No | Title | Solution | Difficulty |
|---|---|---|---|
| 101 | Symmetric Tree | Java 遍历,Java 递归 | Easy |
| 102 | Binary Tree Level Order Traversal | Java | Medium |
| 108 | Convert Sorted Array to Binary Search Tree | Java | Easy |
| 110 | Balanced Binary Tree | Java | Easy |
| 111 | Minimum Depth of Binary Tree | Java | Easy |
| 112 | Path Sum | Java | Easy |
| 129 | Sum Root to Leaf Numbers | Java | Easy |
| 199 | Binary Tree Right Side View | Java | Medium |
| 222 | Count Complete Tree Nodes | Java | Medium |
| 235 | Lowest Common Ancestor of a Binary Search Tree | Java | Easy |
| 257 | Binary Tree Paths | Java | Easy |
| 404 | Sum of Left Leaves | Java | Easy |
| 437 | Path Sum III | Java | Easy |
| 450 | Delete Node in a BST | Java | Medium |
- 递归回溯 - Recursion
| No | Title | Solution | Difficulty |
|---|---|---|---|
| 17 | Letter Combinations of a Phone Number | Java 遍历,Java 递归 | Medium |
| 37 | Sudoku Solver | Hard | |
| 39 | Combination Sum | Medium | |
| 46 | Permutations | Java | Medium |
| 47 | Permutations II | Java | Medium |
| 51 | N-Queens | Hard | |
| 77 | Combinations | Java | Medium |
| 79 | Word Search | Java | Medium |
| 200 | Number of Islands | Java | Medium |
- 动态规划 - Dynamic programming
| No | Title | Solution | Difficulty |
|---|---|---|---|
| 64 | Minimum Path Sum | Medium | |
| 65 | Valid Number | Hard | |
| 70 | Climbing Stairs | Java | Easy |
| 120 | Triangle | Medium | |
| 139 | Word Break | Medium | |
| 198 | House Robber | Easy | |
| 213 | House Robber II | Medium | |
| 279 | Perfect Squares | Medium | |
| 300 | Longest Increasing Subsequence | Medium | |
| 309 | Best Time to Buy and Sell Stock with Cooldown | Medium | |
| 343 | Integer Break | Java | Medium |
| 416 | Partition Equal Subset Sum | Medium | |
| 494 | Target Sum | Medium |
- 贪心算法 - Greedy algorithm
| No | Title | Solution | Difficulty |
|---|---|---|---|
| 392 | Is Subsequence | Java | Medium |
| 435 | Non-overlapping Intervals | Java | Medium |
| 455 | Assign Cookies | Java | Easy |
- 图论 - Graph theory
| No | Title | Solution | Difficulty |
|---|---|---|---|
| 126 | Word Ladder II | Medium | |
| 127 | Word Ladder | Medium | |
| 133 | Clone Graph | Medium | |
| 279 | Perfect Squares | Medium | |
| 542 | 01 Matrix | Medium | |
| 690 | Employee Importance | Easy |