本文章是一个系列，主要记录自己解算法题的一个记录，每道题会出一篇解题报告，作为自己算法功底的沉淀。每次迭代全部从头开始，并且记录以日期。
下面记录的必须在ide和lintcode上提交过，并且写过代码的。
解题七步曲：1 倾听问题，2样本确认， 3 动口不动手的暴力天然解， 4 动口也动手的最优解，5 路演你的思路，6 结构化的编码，7 单元测试
我的笔记：here (复习时候，刷这个效率更高)
我AC的题目：here
| No | Problem | Describe | Type | Diffculty | Note | Date1 | Date2 | Date3 |
|---|---|---|---|---|---|---|---|---|
| 1 | 13-implement-strstr | 字符串查找 | string | Easy | 2020/6/19 | |||
| 2 | 594-strstr-ii | 字符串查找 II | hash,kmp | Hard | 2020/6/19 | |||
| 3 | 17-subsets | 子集(无重复) | combination,dfs | Medium | 2020/6/19 | |||
| 4 | 18-subsets-ii | 子集 II(有重复) | dfs,backtracking | Medium | 2020/6/19 | |||
| 5 | 1361-text-justification | 文字并排 | simulation | Hard | 2020/6/19 | |||
| 6 | 38-search-a-2d-matrix-ii | 搜索二维矩阵 II | sort-matrix | Medium | 2020/6/19 | |||
| 7 | 39-recover-rotated-sorted-array | 恢复旋转排序数组 | sort-array | Easy | 2020/6/19 | |||
| 8 | 573-build-post-office-ii | 邮局的建立 II | bfs | Medium | 2020/6/21 | |||
| 9 | 616-course-schedule-ii | 安排课程 | bfs,topological-sort | Medium | 2020/6/21 | |||
| 10 | 598-zombie-in-matrix | 僵尸矩阵 | bfs | Medium | 2020/6/21 | |||
| 11 | 127-topological-sorting | 拓扑排序 | bfs or dfs | Medium | 2020/6/21 | |||
| 12 | 433-number-of-islands | 岛屿的个数 | bfs or union-find | Easy | 2020/6/21 | |||
| 13 | 677-number-of-big-islands | 大岛的数量 | bfs | Medium | 2020/6/22 | |||
| 14 | 109-triangle | 数字三角形 | dp，坐标型 | Medium | 2020/6/22 | |||
| 15 | 110-minimum-path-sum | 最小路径和 | dp | Easy | 2020/6/22 | |||
| 16 | 114-unique-paths | 不同的路径 | dp，坐标型号dp | Easy | 2020/6/22 | |||
| 17 | 99-reorder-list | 重排链表 | LinkedList | Medium | 2020/6/22 | |||
| 18 | 174-remove-nth-node-from-end-of-list | 删除链表中倒数第n个节点 | LinkedList | Easy | 2020/6/23 | |||
| 19 | 102-linked-list-cycle | 带环链表 | LinkedList | Medium | 2020/6/23 | |||
| 20 | 103-linked-list-cycle-ii | 带环链表 返回环起点值 | LinkedList | Hard | 2020/6/23 | |||
| 21 | 104-merge-k-sorted-lists | 合并k个排序链表 | LinkedList | Medium | 2020/6/23 | |||
| 22 | 105-copy-list-with-random-pointer | 复制带随机指针的链表 | LinkedList | Medium | 2020/6/23 | |||
| 23 | 106-convert-sorted-list-to-binary-search-tree | 有序链表转换为二叉搜索树 | LinkedList | Medium | 2020/6/23 | |||
| 24 | 177-convert-sorted-array-to-binary-search-tree-with-minimal-height | 把排序数组转换为高度最小的二叉搜索树 | LinkedList | Easy | 2020/6/23 | |||
| 25 | 74 first-bad-version | 第一个错误的代码版本 | binarysearch | Medium | 2020/6/24 | |||
| 26 | 1496 implement-rand10-using-rand7 | 用Rand7()实现Rand10() | simulation | Medium | 2020/6/24 | |||
| 27 | 66 binary-tree-preorder-traversal | 二叉树的前序遍历 | Tree，recursion and iteration(Stack) | Easy | 2020/6/24 | |||
| 28 | 67 binary-tree-inorder-traversal | 二叉树的中序遍历 | Tree，recursion and iteration(Stack) | Easy | 2020/6/24 | |||
| 29 | 68 binary-tree-postorder-traversal | 二叉树的后序遍历 | Tree，recursion and iteration(Stack) | Easy | 2020/6/24 | |||
| 30 | 86 binary-search-tree-iterator | 二叉查找树迭代器 | Tree | Hard | 2020/6/24 | |||
| 31 | 97 maximum-depth-of-binary-tree | 二叉树的最大深度 | DC | Easy | 2020/6/24 | |||
| 32 | 93 balanced-binary-tree | 是否是平衡二叉树 | DC，Recursion | Easy | 2020/6/24 | |||
| 33 | 31 partition-array | 数组划分 | Array,Quick Sort，Two Pointer | Medium | 2020/6/25 | |||
| 34 | 94 binary-tree-maximum-path-sum | 二叉树中的最大路径和 | DC | Medium | 2020/6/25 | |||
| 35 | 88 lowest-common-ancestor-of-a-binary-tree | 最近公共祖先(LCA) | DC,RE，LCA | Medium | 2020/6/25 | |||
| 36 | 69 binary-tree-level-order-traversal | 二叉树的层次遍历 | BFS,Queue | Easy | 2020/6/25 | |||
| 37 | 70 binary-tree-level-order-traversal-ii | 二叉树的层次遍历 II | BFS | Medium | 2020/6/25 | |||
| 38 | 95 validate-binary-search-tree | 验证二叉查找树 | traversal | Medium | 2020/6/25 | |||
| 39 | 85 insert-node-in-a-binary-search-tree | 在二叉查找树中插入节点 | BST，分治 | Medium | 2020/6/25 | |||
| 40 | 86 binary-search-tree-iterator | 在二叉查找树中插入节点 | BST，分治 | Hard | 2020/6/25 | |||
| 41 | 87 remove-node-in-binary-search-tree | 删除二叉查找树的节点 | BST，分治 | Hard | 2020/6/25 | |||
| 42 | 11 search-range-in-binary-search-tree | 二叉查找树中搜索区间 | tree-traversal | Medium | 2020/6/25 | |||
| 42 | 12 min-stack | 最小栈 | stack，Simulation | Medium | 2020/6/25 | |||
| 43 | 40 implement-queue-by-two-stacks | 双栈实现队列 | stack，Simulation | Medium | 2020/6/25 | |||
| 44 | 494-implement-stack-by-two-queues | 双队列实现栈 | queue | Medium | 2020/6/25 | |||
| 45 | 130 heapify | 堆化 | heap | Medium | 2020/6/25 | |||
| 46 | 158 valid-anagram | 两个字符串是变位词 | string,map | Easy | 2020/6/26 | |||
| 47 | 122 largest-rectangle-in-histogram | 直方图最大矩形覆盖 | monotonic stack | Hard | 2020/6/26 | |||
| 48 | 126-max-tree | 最大树 | monotonic stack | Hard | 2020/6/26 | |||
| 49 | 134-lru cache | LRU缓存策略 | hash | Hard | 2020/6/26 | |||
| 50 | 24-lfu cache | LFU缓存 | hash | Hard | 2020/6/26 | |||
| 51 | 129-rehashing | 重哈希 | hash | Medium | 2020/6/26 | |||
| 52 | 171-anagrams | 变位词 | hash | Medium | 2020/6/26 | |||
| 53 | 138-subarray-sum | 子数组之和 | hash，前缀和 | Easy | 2020/6/26 | |||
| 54 | 124-longest-consecutive-sequence | 最长连续序列 | hash | Medium | 2020/6/26 | 2021/2/13 | ||
| 55 | 81-find-median-from-data-stream | 数据流中位数 | heap | Hard | 2020/6/26 | |||
| 56 | 132-word-search-ii | 单词搜索 II | trie | Hard | 2020/6/26 | |||
| 57 | 442-implement-trie-prefix-tree | 实现 Trie（前缀树） | trie | 2020/6/27 | ||||
| 58 | 61-search-for-a-range | 搜索区间(对比138) | binarysearch | Medium | 2020/6/27 | 2021/2/13 | ||
| 59 | 60-search-insert-position | 搜索插入位置 | binarysearch | Easy | 2020/6/27 | |||
| 60 | 28-search-a-2d-matrix | 搜索二维矩阵 | binarysearch | Easy | 2020/6/27 | |||
| 61 | 75-find-peak-element | 寻找峰值 | binarysearch | Medium | 2020/6/27 | |||
| 62 | 62-search-in-rotated-sorted-array(无重复) | 搜索旋转排序数组 | binarysearch | Medium | 2020/6/27 | |||
| 63 | 63-search-in-rotated-sorted-array-ii(有重复) | 搜索旋转排序数组 | 62 follow up | Medium | 2020/6/27 | |||
| 64 | 6-merge-two-sorted-arrays | 合并排序数组 II | Two Pointers | Easy | 2020/6/27 | |||
| 65 | 64-merge-sorted-array | 合并排序数组 | Two Pointers | Easy | 2020/6/27 | |||
| 66 | 159-find-minimum-in-rotated-sorted-array | 寻找旋转排序数组中的最小值(无重复) | binarysearch | Medium | 2020/6/27 | |||
| 67 | 160-find-minimum-in-rotated-sorted-array-ii | 寻找旋转排序数组中的最小值(有重复) | binarysearch | Medium | 2020/6/27 | |||
| 68 | 65-median-of-two-sorted-arrays | 两个排序数组的中位数 | binarysearch,FindKMax | Hard | 2020/6/27 | |||
| 69 | 8-rotate-string | 旋转字符串 | string，simulation，三步翻转法 | Easy | 2020/6/27 | |||
| 70 | 53-reverse-words-in-a-string | 翻转字符串中的单词 | string | Easy | 2020/6/27 | |||
| 71 | 241-string-to-integer | 转换字符串到整数 | string | Easy | 2020/6/28 | |||
| 72 | 1510-buddy-strings | 亲密字符串 | string | Easy | 2020/6/28 | |||
| 73 | 415-valid-palindrome | 有效回文串 | string，双指针 | Medium | 2020/6/28 | |||
| 74 | 767-reverse-array | 翻转数组 | string，reverse | Easy | 2020/6/28 | |||
| 75 | 1283-reverse-string | 翻转字符串 | string，reverse | Easy | 2020/6/28 | |||
| 76 | 78-longest-common-prefix | 最长公共前缀 (LCP) | string。Simulation | Medium | 2020/6/28 | |||
| 77 | 1263-is-subsequence | 是子序列吗 | string，Simulation | Medium | 2020/6/28 | |||
| 78 | 384-longest-substring-without-repeating-characters | 最长无重复字符的子串 | string，two pointer | Medium | 2020/6/29 | 2021/2/14 | ||
| 79 | 213-string-compression | 字符串压缩 | string | Easy | 2020/6/29 | |||
| 80 | 1352-compare-version-numbers | 比较版本号 | string | Medium | 2020/6/29 | |||
| 81 | 1542-nexttime-norepeat | 下一个不重复的时间 | string | Medium | 2020/6/29 | |||
| 82 | 192-wildcard-matching | 通配符匹配 | string，DFS | Hard | 2020/6/30 | |||
| 83 | 98-sort-list（排序链表） | 链表排序(归并和快速) | sort | Medium | 2020/6/30 | |||
| 84 | 463-sort-integers | 整数排序 | sort【直接选择(选择)，冒泡排序(交换)，直接插入排序(插入)】 | Native | 简单排序 | 2020/6/30 | ||
| 85 | 464-sort-integers-ii | 整数排序2 | sort【堆排序(选择)，快排(交换)，归并排序(归并)】 | Medium | 分治排序 | 2020/6/30 | ||
| 86 | 136-palindrome-partitioning | 分割回文串 | 组合型DFS+Backtracking | Medium | 2020/7/1 | |||
| 87 | 77-longest-common-subsequence | 最长公共子序列(LCS) | match-dp | Medium | 2020/7/2 | |||
| 88 | 79-longest-common-substring | 最长公共子串(LCS) | Two Sequences DP | Medium | 2020/7/2 | |||
| 89 | 680-spilt-string | 分割字符串 | 组合型DFS+Backtracking | Medium | 2020/7/2 | |||
| 90 | 15-permutations | 全排列 | 排列型DFS+Backtracking | Medium | 2020/7/2 | |||
| 91 | 16-permutations-ii | 全排列 | 排列型DFS+Backtracking | Medium | 2020/7/2 | |||
| 92 | 669-coin-change | 换硬币 | 无限背包,DFS,DP,不用回溯 | 2020/7/3 | ||||
| 93 | 816-traveling-salesman-problem | 旅行商问题 | 排列型DFS，pruning,dp,旅行售货员问题，TSP问题，组合优化 | Hard | 2020/7/3 | |||
| 94 | 1147-work-plan | 工作安排 | coordinate-dp | Medium | 2020/7/3 | |||
| 95 | 76-longest-increasing-subsequence | 最长上升子序列(LIS) | match-dp，LIS | Medium | 2020/7/3 | |||
| 96 | 91-minimum-adjustment-cost | 最小调整代价 | dp | Medium | 2020/7/3 | |||
| 97 | 34-n-queens-ii | N皇后问题（方案数） | Backtracking+DFS | Medium | 2020/7/4 | |||
| 98 | 33-n-queens | N皇后问题（具体方案） | Backtracking+DFS | Medium | 2020/7/4 | |||
| 99 | 622-frog-jump | 青蛙跳 | DFS，DP | Hard | 2020/7/4 | |||
| 100 | 602-russian-doll-envelopes | 俄罗斯套娃信封 | dfs(指数级),dp(正解) | Hard | 2020/7/4 | |||
| 101 | 116-jump-game | 跳跃游戏 | 单序列dp(可行性)，贪心 | Medium | 2020/7/4 | |||
| 102 | 117-jump-game-ii | 跳跃游戏 | 单序列dp(最小值) | Medium | 2020/7/4 | |||
| 103 | 149-best-time-to-buy-and-sell-stock | 买卖股票的最佳时机（一次交易） | 单序列dp(最大值) | Medium | 2020/7/4 | |||
| 104 | 115-unique-paths-ii | 不同的路径 II | 坐标DP | Easy | 2020/7/4 | |||
| 105 | 111-climbing-stairs | 爬楼梯 | 单序列dp(计数问题) | Easy | 2020/7/4 | |||
| 106 | 563-backpack-v | 背包问题 V | Backpack DP | Medium | 2020/7/4 | |||
| 107 | 630-knight-shortest-path-ii | 骑士的最短路径II | 坐标dp, 单向BFS->双向BFS | Medium | 2020/7/6 | |||
| 108 | 564-combination-sum-iv(backpack-vi) | 组合总和 IV | 单序列dp，Backpack DP | Medium | 2020/7/6 | |||
| 109 | 512-decode-ways | 解码方法 | dp | Medium | 2020/7/7 | |||
| 110 | 589-connecting-graph | 连接图 | union-find | Medium | 2020/7/7 | 2021/2/14 | ||
| 111 | 752-rogue-knight-sven | 流浪剑客斯温 | dp | Medium | 2020/7/7 | |||
| 112 | 590-connecting-graph-ii | 连接图 | union-find | Medium | 2020/7/8 | |||
| 113 | 360-sliding-window-median | 滑动窗口的中位数 | heap，Sliding Window | Hard | 2020/7/8 | |||
| 114 | 401-kth-smallest-number-in-sorted-matrix | 排序矩阵中的从小到大第k个数 | heap | Medium | 2020/7/8 | |||
| 115 | 362-sliding-window-maximum | 滑动窗口的最大值 | monotonic-queue | Hard | 2020/7/8 | |||
| 116 | 178-graph-valid-tree | 图是否是树 | union-find | Medium | 2020/7/8 | |||
| 117 | 434-number-of-islands-ii | 岛屿的个数II | union-find | Medium | 2020/7/9 | |||
| 118 | 430-scramble-string | 攀爬字符串 | dfs+pruning | Hard | 2020/7/9 | |||
| 119 | 802-sudoku-solver | 数独 | dfs+pruning+backtracking | Hard | 2020/7/10 | |||
| 120 | 121-word-ladder-ii | 单词接龙 II | dfs+pruning+backtracking | Hard | 2020/7/10 | |||
| 121 | 582-word-break-ii | 单词拆分II | dfs+pruning+backtracking | Hard | 2020/7/11 | |||
| 122 | 652-factorization | 因式分解 | dfs+pruning+backtracking | Medium | 2020/7/11 | |||
| 123 | 119-edit-distance | 编辑距离 | 匹配性dp | Medium | 2020/7/11 | |||
| 124 | 787-the-maze | 迷宫 | bfs | Medium | 2020/7/11 | |||
| 125 | 788-the-maze-ii | 迷宫 | bfs | Medium | 2020/7/11 | |||
| 126 | 789-the-maze-iii | 迷宫 | bfs | Hard | 2020/7/11 | |||
| 127 | 691-recover-binary-search-tree | 恢复二叉搜索树 | bst | Medium | 2020/7/12 | |||
| 128 | 82-single-number | 落单的数2n*1,两次 | bit，hash | Easy | 2020/7/12 | |||
| 129 | 83-single-number-ii | 落单的数 II 3n*1，三次 | bit，hash | Medium | 2020/7/12 | |||
| 130 | 84-single-number-iii | 落单的数2*n + 2 | bit，hash | Medium | 2020/7/12 | |||
| 131 | 46-majority-element | 主元素(不是众数) 1/2 | Enumerate | Easy | 2020/7/12 | |||
| 132 | 1018-champagne-tower(triangle) | 香槟塔 | 二维坐标dp | Medium | 2020/7/12 | |||
| 133 | 200-longest-palindromic-substring | 最长回文子串 | 区间dp | Medium | 2020/7/14 | |||
| 134 | 1565-modern-ludo-i | 飞行棋 I | 一维坐标dp | Medium | 2020/7/16 | |||
| 135 | 1141-the-months-days | 月份天数 | 闰年 | Easy | 2020/7/16 | |||
| 136 | 254-drop-eggs | 丢鸡蛋 | 归纳法 | Easy | 2020/7/16 | |||
| 137 | 47-majority-element-ii | 主元素1/3 | Enumerate | Medium | 2020/7/19 | |||
| 138 | 48-majority-element-iii | 主元素1/k | HashTable | Medium | 2020/7/20 | |||
| 139 | 150-best-time-to-buy-and-sell-stock-ii | 买卖股票的最佳时机 II(多次交易) | 贪心 | Medium | 2020/7/20 | |||
| 140 | 151-best-time-to-buy-and-sell-stock-iii | 买卖股票的最佳时机 III(两笔交易) | Enumerate | Medium | 2020/7/20 | |||
| 141 | 393-best-time-to-buy-and-sell-stock-iv | 买卖股票的最佳时机 III(K笔交易) | dp | Medium | 2020/7/20 | |||
| 142 | 44-minimum-subarray | 最小子数组 | 贪心 | Easy | 2020/7/20 | |||
| 143 | 45-maximum-subarray-difference | 最大子数组差 | 贪心 | Easy | 2020/7/20 | |||
| 144 | 138-subarray-sum | 子数组之和 | hashmap | Easy | 2020/7/20 | |||
| 145 | 139-subarray-sum-closest | 最接近零的子数组和 | Two Pointers，hashmap | Medium | 2020/7/20 | |||
| 146 | 56-two-sum | 两数之和 | Two Pointers | Easy | 2020/7/20 | |||
| 147 | 608-two-sum-ii-input-array-is-sorted | 两数和 II-输入已排序的数组 | Two Pointers | Medium | 2020/7/20 | |||
| 148 | 57-3sum | 三数之和 | Two Pointers | Medium | 2020/7/20 | |||
| 149 | 533-two-sum-closest-to-target | 两数和的最接近值 | Two Pointers | Medium | 2020/7/20 | |||
| 150 | 89-k-sum | K数之和 | dp | Hard | 2020/7/20 | |||
| 151 | 140-fast-power | 快速幂 | DC | Medium | 2020/7/21 | |||
| 152 | 1324-count-primes | 质数的个数 | Mathmatics | Easy | 2020/7/21 | |||
| 153 | 141-sqrtx | 对x开根 | Mathmatics | Easy | 2020/7/21 | |||
| 154 | 2-trailing-zeros | 尾部的零 | Mathmatics | Easy | 2020/7/21 | |||
| 155 | 142.o1-check-power-of-2 | O(1)时间检测2的幂次 | Binary | Easy | 2020/7/21 | |||
| 156 | 49-sort-letters-by-case | 字符大小写排序 | Two Pointers | Medium | 2020/7/21 | |||
| 157 | 1563-shortest-path-to-the-destination | 目的地的最短路径 | bfs | Medium | 2020/7/21 | |||
| 158 | 108-palindrome-partitioning-ii | 分割回文串 II | dp | Medium | 2020/8/2 | |||
| 159 | 107-word-break | 单词拆分 I | dp | Medium | 2020/8/2 | |||
| 160 | 41-maximum-subarray | 最大子数组 | dp | Easy | 2020/8/3 | |||
| 161 | 29-interleaving-string | 交叉字符串 | dp | Medium | 2020/8/9 | |||
| 162 | 513-perfect-squares | 完美平方 | dp | Medium | 2020/8/9 | |||
| 163 | 394-coins-in-a-line | 硬币排成线 | dp | Medium | 2020/8/9 | |||
| 164 | 92-backpack | 背包问题 | dp | Medium | 2020/8/9 | |||
| 165 | 118-distinct-subsequences | 不同的子序列 | dp | Medium | 2020/8/9 | |||
| 166 | 604-window-sum | 滑动窗口内数的和 | two-pointer | Easy | 2020/8/9 | |||
| 167 | 539-move-zeroes | 移动0 | two-pointer | Easy | 2020/8/10 | |||
| 168 | 521.remove-duplicate-numbers-in-array | 数组去重 | two-pointer | Easy | 2020/8/10 | |||
| 169 | 638. Isomorphic Strings | 字符同构 | string | Easy | 2021/2/10 | |||
| 170 | 626. Rectangle Overlap | 矩形重叠 | string | Easy | 2021/2/10 | |||
| 171 | 637. Valid Word Abbreviation | 检查缩写单词 | string | Easy | 2021/2/10 | |||
| 172 | 639. Word Abbreviation | 单词缩写 | string | Hard | 2021/2/11 | |||
| 173 | 642. Moving Average from Data Stream | 数据流滑动窗口平均值 | Prefix Sum Array，rolling array | Easy | 2021/2/11 | |||
| 174 | 644. Strobogrammatic Number | 镜像数字 | Enumerate | Easy | 2021/2/11 | |||
| 175 | 640. One Edit Distance | 一次编辑距离 | Enumerate | Medium | 2021/2/11 | |||
| 176 | 660. Read N Characters Given Read4 | 用Read4从文件中读取N个字符 II-多次调用 | Enumerate | Hard | 2021/2/12 | |||
| 177 | 659. Encode and Decode Strings | 编码和解码字符串 | Enumerate | Medium | 2021/2/12 | |||
| 178 | 419. Roman to Integer | 罗马数字转整数 | Enumerate | Medium | 2021/2/12 | |||
| 179 | 418. Integer to Roman | 整数转罗马数字 | Enumerate | Medium | 2021/2/12 | |||
| 180 | 645. Find the Celebrity | 识别名人 | Enumerate | Medium | 2021/2/12 | |||
| 181 | 641. Missing Ranges | 丢失的间隔 | Enumerate | Medium | 2021/2/12 | |||
| 182 | 156. Merge Intervals | 合并区间 | Enumerate | Easy | 2021/2/12 | |||
| 183 | 30. Insert Interval | 插入区间 | Enumerate | Medium | 2021/2/12 | |||
| 184 | 646. First Position Unique Character | 第一个不重复字符位置 | Hash | Easy | 2021/2/12 | |||
| 185 | 647. Find All Anagrams in a String | 子串字谜 | Hash+Siding Windows | Medium | 2021/2/12 | |||
| 186 | 423. Valid Parentheses | 有效的括号序列 | Stack | Easy | 2021/2/13 | |||
| 187 | 526. Load Balancer | 负载均衡 | DS | 2021/2/13 | ||||
| 188 | 662. Guess Number Higher or Lower | 猜数游戏 | Binary Search | Easy | 2021/2/13 | |||
| 189 | 661. Convert BST to Greater Tree | 把二叉搜索树转化成更大的树 | BST | Easy | 2021/2/13 | |||
| 190 | 649. Binary Tree Upside Down | 二叉树翻转 | BST | Medium | 2021/2/13 | |||
| 191 | 650. Find Leaves of Binary Tree | 二叉树叶子顺序遍历 | BST | Medium | 2021/2/13 | |||
| 192 | 651. Binary Tree Vertical Order Traversal | 二叉树垂直遍历 | Hash+BFS | Medium | 2021/2/13 | |||
| 193 | 448. Inorder Successor in BST | 二叉查找树的中序后继 | BST | Medium | 2021/2/13 | |||
| 194 | 477. Surrounded Regions | 被围绕的区域 | BFS | Medium | 2021/2/13 | |||
| 195 | 663. Walls and Gates | 墙和门 | BFS | Medium | 2021/2/13 | |||
| 196 | 32. Minimum Window Substring | 最小子串覆盖 | Two pointer | Medium | 2021/2/14 | |||
| 197 | 543. Kth Largest in N Arrays | N数组第K大元素(一个数组第K大) | Heap | Hard | 2021/2/14 | |||
| 198 | 465. Kth Smallest Sum In Two Sorted Arrays | 两个排序数组和的第K小 | Heap | Hard | 2021/2/14 | |||
| 199 | 591. Connecting Graph III | 连接图 III | UF | Medium | 2021/2/14 | |||
| 200 | 1179. Friend Circles | 朋友圈 | UF | Medium | 2021/2/14 | |||
| 201 | 152. Combinations | 组合 | DFS，组合 | Medium | 2021/2/15 | |||
| 202 | 135. Combination Sum I | 组合数之和 | DFS，组合 | Medium | 2021/2/15 | |||
| 203 | 153. Combination Sum II | 组合数之和 | DFS，组合 | Medium | 2021/2/15 | |||
| 204 | 1321. Combination Sum III | 组合数之和 | DFS，组合 | Medium | 2021/2/15 | |||
| 205 | 457. Classical Binary Search | 经典二分查找问题 | Binary Search | Easy | 2021/2/15 | |||
| 206 | 366. Fibonacci | 斐波那契 | iteration/recursion,多项公式 | Naive | 2021/2/16 | |||
| 207 | 1807. Fibonacci easy | 斐波那契 | iteration | Easy | 2021/2/16 | |||
| 208 | 428. Pow(x, n) | x的n次幂 | recursion,decrease-and-conquer | Medium | 2021/2/16 | |||
| 209 | 451. Swap Nodes in Pairs | 两两交换链表中的节点 | 2021/2/16 | |||||
| 210 | 450. Reverse Nodes in k-Group | K组翻转链表 | 2021/2/16 | |||||
| 211 | 1425. Backspace String Compare | 比较含退格的字符串 | 2021/2/16 | |||||
| 212 | 5.Kth Largest Element | 数组第k大元素 | 2021/2/16 | |||||
| 213 | 471. Top K Frequent Words | 最高频的K个单词 | 2021/2/16 | |||||
| 214 | 1311. Lowest Common Ancestor of a Binary Search Tree | 二叉搜索树的最近公共祖先 | Easy | 2021/2/16 | ||||
| 215 | 1509. Lemonade Change | 柠檬水找零 | Greedy | Easy | 2021/2/16 | |||
| 216 | 1230. Assign Cookies | 分饼干 | Greedy | Easy | 2021/2/16 | |||
| 217 | 1493. Walking Robot Simulation | 模拟行走机器人 | Greedy | 2021/2/16 | ||||
| 218 | 155. Minimum Depth of Binary Tree | 二叉树的最小深度 | 2021/2/16 | |||||
| 219 | 1360. Symmetric Tree | 对称树 | 2021/2/16 | |||||
| 220 | 1244. Minimum Genetic Mutation | 最小基因变化 | 2021/2/16 | |||||
| 221 | 427. Generate Parentheses | 生成括号 | 2021/2/16 | |||||
| 222 | 1195. Find Largest Value in Each Tree Row | 找出树中每行的最大值 | Medium | 2021/2/16 | ||||
| 223 | 120. Word Ladder | 单词接龙 | 2021/2/16 | |||||
| 224 | 615. Course Schedule | 课程表 | 2021/2/16 | |||||
| 225 | 1189. Minesweeper | 扫雷游戏 | BFS | Medium | 2021/2/16 | |||
| 226 | 389. Valid Sudoku | 判断数独是否合法 | Simulation | Easy | 2021/2/16 | |||
| 227 | 123. Word Search | 单词搜索 | DFS | Medium | 2021/2/16 | |||
| 228 | 664. Counting Bits | 数 1 | Bit，DP | Medium | 2021/2/16 | |||
| 229 | 191. Maximum Product Subarray | 乘积最大子序列 | 线性dp | Medium | 2021/2/16 | |||
| 230 | 556. Standard Bloom Filter | 标准型布隆过滤器 | Medium | 2021/2/16 | ||||
| 231 | 555. Counting Bloom Filter | 计数型布隆过滤器 | Medium | 2021/2/16 | ||||
| 232 | 1332. Number of 1 Bits | 判断一个整数中有多少个1 | Bit | Easy | 2021/2/16 | |||
| 233 | 204. Singleton | 单例 | OOD | Easy | 2021/2/16 | |||
| 234 | 496. Toy Factory | 工厂 | OOD | Easy | 2021/2/16 | |||
| 235 | 175. Invert Binary Tree | 反转二叉树 | Tree | Easy | 2021/2/16 | |||