● Easy
● Medium
● Hard
★ 必刷高频
| 编号 | 题目 | 类型 | 难度 | 考察点 |
|---|
| 1 | Two Sum ★ | ArrayHashMap | Medium | HashMap，O(n) 解法 |
| 15 | 3Sum ★ | Array | Medium | 排序+双指针，去重逻辑 |
| 42 | Trapping Rain Water ★ | Array | Hard | 双指针/单调栈，经典 |
| 53 | Maximum Subarray ★ | DP | Medium | Kadane算法，变体超多 |
| 121 | Best Time to Buy and Sell Stock ★ | Array | Easy | QR必考，还要会 123/188 |
| 123 | Best Time to Buy/Sell Stock III | DP | Hard | 状态机DP，最多2笔交易 |
| 76 | Minimum Window Substring | Sliding Window | Hard | 滑窗模板题 |
| 560 | Subarray Sum Equals K ★ | ArrayPrefixSum | Medium | 前缀和+HashMap |
| 239 | Sliding Window Maximum | Deque | Hard | 单调双端队列 |
| 238 | Product of Array Except Self | Array | Medium | 前后缀积，不用除法 |
| 编号 | 题目 | 类型 | 难度 | 考察点 |
|---|
| 70 | Climbing Stairs ★ | DP | Easy | 入门，Fibonacci变体 |
| 322 | Coin Change ★ | DP | Medium | 完全背包，经典 |
| 300 | Longest Increasing Subsequence ★ | DP | Medium | O(nlogn) 二分优化要会 |
| 72 | Edit Distance | DP | Medium | 字符串DP经典 |
| 312 | Burst Balloons | DP | Hard | 区间DP，思维难 |
| 10 | Regular Expression Matching | DP | Hard | 高频难题 |
| 174 | Dungeon Game | DP | Hard | 反向DP思路 |
| 188 | Best Time to Buy/Sell Stock IV ★ | DP | Hard | 状态机DP，最多k笔 |
| 152 | Maximum Product Subarray | DP | Medium | 维护最大最小值 |
| 编号 | 题目 | 类型 | 难度 | 考察点 |
|---|
| 470 | Implement Rand10 Using Rand7 ★ | Probability | Medium | 拒绝采样，QR必考 |
| 398 | Random Pick Index ★ | Reservoir | Medium | 水库抽样 |
| 382 | Linked List Random Node | Reservoir | Medium | 水库抽样变体 |
| 50 | Pow(x, n) ★ | Math | Medium | 快速幂，处理负数 |
| 149 | Max Points on a Line | Math | Hard | 斜率，精度处理 |
| 191 | Number of 1 Bits | Bit | Easy | 位运算基础 |
| 136 | Single Number | Bit | Easy | XOR技巧 |
| 268 | Missing Number | Math | Easy | 多种解法 |
| 编号 | 题目 | 类型 | 难度 | 考察点 |
|---|
| 200 | Number of Islands ★ | Graph | Medium | BFS/DFS/Union Find |
| 207 | Course Schedule ★ | Graph | Medium | 拓扑排序，检测环 |
| 124 | Binary Tree Maximum Path Sum | Tree | Hard | 后序遍历 |
| 236 | Lowest Common Ancestor | Tree | Medium | 经典递归 |
| 297 | Serialize and Deserialize Binary Tree | Tree | Hard | BFS序列化 |
| 127 | Word Ladder | BFS | Hard | 最短路径BFS |
| 399 | Evaluate Division | Graph | Medium | 带权Union Find |
| 编号 | 题目 | 类型 | 难度 | 考察点 |
|---|
| 295 | Find Median from Data Stream ★ | Heap | Hard | 双堆，QR数据流场景 |
| 23 | Merge k Sorted Lists ★ | Heap | Hard | 优先队列 |
| 218 | The Skyline Problem | Heap | Hard | 扫描线+堆 |
| 146 | LRU Cache ★ | Design | Medium | HashMap+双向链表 |
| 460 | LFU Cache | Design | Hard | LRU进阶 |
| 347 | Top K Frequent Elements ★ | Heap | Medium | 桶排序/堆 |
| 373 | Find K Pairs with Smallest Sums | Heap | Medium | 多路归并 |
| 编号 | 题目 | 类型 | 难度 | 考察点 |
|---|
| 46 | Permutations ★ | Backtrack | Medium | 全排列模板 |
| 78 | Subsets | Backtrack | Medium | 子集枚举 |
| 22 | Generate Parentheses ★ | Backtrack | Medium | 括号合法性 |
| 5 | Longest Palindromic Substring | String | Medium | 中心扩展/Manacher |
| 438 | Find All Anagrams in a String | Sliding Window | Medium | 滑窗+频率表 |
| 编号 | 题目 | 类型 | 难度 | 考察点 |
|---|
| 33 | Search in Rotated Sorted Array ★ | Binary Search | Medium | 变体很多 |
| 4 | Median of Two Sorted Arrays ★ | Binary Search | Hard | O(log(m+n))，经典难题 |
| 378 | Kth Smallest in a Sorted Matrix | Binary Search | Medium | 值域二分 |
| 410 | Split Array Largest Sum | Binary Search | Hard | 最小化最大值，二分答案 |