| 3. 无重复字符的最长子串 | 3 | https://leetcode-cn.com/problems/longest-substring-without-repeating-characters |
| 142. 环形链表 II | 2 | https://leetcode-cn.com/problems/linked-list-cycle-ii |
| 20. 有效的括号 | 2 | https://leetcode-cn.com/problems/valid-parentheses |
| 53. 最大子序和 | 1 | https://leetcode-cn.com/problems/maximum-subarray |
| 232. 用栈实现队列 | 1 | https://leetcode-cn.com/problems/implement-queue-using-stacks |
| 15. 三数之和 | 1 | https://leetcode-cn.com/problems/3sum |
| 补充题6. 手撕堆排序 | 1 | |
| 509. 斐波那契数 | 1 | https://leetcode-cn.com/problems/fibonacci-number |
| 206. 反转链表 | 1 | https://leetcode-cn.com/problems/reverse-linked-list |
| 剑指 Offer 48. 最长不含重复字符的子字符串 | 1 | https://leetcode-cn.com/problems/zui-chang-bu-han-zhong-fu-zi-fu-de-zi-zi-fu-chuan-lcof |
| 143. 重排链表 | 1 | https://leetcode-cn.com/problems/reorder-list |
| 349. 两个数组的交集 | 1 | https://leetcode-cn.com/problems/intersection-of-two-arrays |
| 剑指 Offer 42. 连续子数组的最大和 | 1 | https://leetcode-cn.com/problems/lian-xu-zi-shu-zu-de-zui-da-he-lcof |
| 121. 买卖股票的最佳时机 | 1 | https://leetcode-cn.com/problems/best-time-to-buy-and-sell-stock |
| 5. 最长回文子串 | 1 | https://leetcode-cn.com/problems/longest-palindromic-substring |
| 39. 组合总和 | 1 | https://leetcode-cn.com/problems/combination-sum |
| 647. 回文子串 | 1 | https://leetcode-cn.com/problems/palindromic-substrings |
| 344. 反转字符串 | 1 | https://leetcode-cn.com/problems/reverse-string |