Career

Algorithm

I - Algorithm

Roadmap

Part 1

  1. LRU Cache
  2. Sign of the Product of an Array
  3. Number of Islands
  4. Two Sum
  5. Reverse Words in a String
  6. Longest Substring Without Repeating Characters
  7. Group Anagrams
  8. Spiral Matrix
  9. Search in Rotated Sorted Array
  10. Valid Parentheses
  11. Find N Unique Integers Sum up to Zero
  12. 3Sum
  13. Letter Combinations of a Phone Number(全排列 + 全排列II)
  14. Serialize and Deserialize Binary Tree Hard
  15. Longest Palindromic Substring Medium 回文
  16. Add Two Numbers Medium
  17. Merge k Sorted Lists Hard
  18. Cinema Seat Allocation Medium
  19. First Missing Positive Hard
  20. String to Integer (atoi) Medium

Part 2

problemoccurrenceslink
215. 数组中的第K个最大元素14https://leetcode-cn.com/problems/kth-largest-element-in-an-array
236. 二叉树的最近公共祖先10https://leetcode-cn.com/problems/lowest-common-ancestor-of-a-binary-tree
206. 反转链表9https://leetcode-cn.com/problems/reverse-linked-list
48. 旋转图像9https://leetcode-cn.com/problems/rotate-image
124. 二叉树中的最大路径和7https://leetcode-cn.com/problems/binary-tree-maximum-path-sum
53. 最大子序和7https://leetcode-cn.com/problems/maximum-subarray
91. 解码方法6https://leetcode-cn.com/problems/decode-ways
151. 翻转字符串里的单词6https://leetcode-cn.com/problems/reverse-words-in-a-string
543. 二叉树的直径6https://leetcode-cn.com/problems/diameter-of-binary-tree
297. 二叉树的序列化与反序列化6https://leetcode-cn.com/problems/serialize-and-deserialize-binary-tree
146. LRU缓存机制5https://leetcode-cn.com/problems/lru-cache
450. 删除二叉搜索树中的节点5https://leetcode-cn.com/problems/delete-node-in-a-bst
22. 括号生成5https://leetcode-cn.com/problems/generate-parentheses
47. 全排列 II5https://leetcode-cn.com/problems/permutations-ii
224. 基本计算器5https://leetcode-cn.com/problems/basic-calculator
468. 验证IP地址4https://leetcode-cn.com/problems/validate-ip-address
110. 平衡二叉树4https://leetcode-cn.com/problems/balanced-binary-tree
94. 二叉树的中序遍历4https://leetcode-cn.com/problems/binary-tree-inorder-traversal
15. 三数之和4https://leetcode-cn.com/problems/3sum
121. 买卖股票的最佳时机4https://leetcode-cn.com/problems/best-time-to-buy-and-sell-stock
39. 组合总和4https://leetcode-cn.com/problems/combination-sum
1. 两数之和4https://leetcode-cn.com/problems/two-sum
3. 无重复字符的最长子串4https://leetcode-cn.com/problems/longest-substring-without-repeating-characters
207. 课程表4https://leetcode-cn.com/problems/course-schedule
138. 复制带随机指针的链表4https://leetcode-cn.com/problems/copy-list-with-random-pointer
69. x 的平方根4https://leetcode-cn.com/problems/sqrtx
240. 搜索二维矩阵 II4https://leetcode-cn.com/problems/search-a-2d-matrix-ii
4. 寻找两个正序数组的中位数3https://leetcode-cn.com/problems/median-of-two-sorted-arrays
103. 二叉树的锯齿形层次遍历3https://leetcode-cn.com/problems/binary-tree-zigzag-level-order-traversal
560. 和为K的子数组3https://leetcode-cn.com/problems/subarray-sum-equals-k
162. 寻找峰值3https://leetcode-cn.com/problems/find-peak-element
62. 不同路径3https://leetcode-cn.com/problems/unique-paths
72. 编辑距离3https://leetcode-cn.com/problems/edit-distance
200. 岛屿数量3https://leetcode-cn.com/problems/number-of-islands
89. 格雷编码3https://leetcode-cn.com/problems/gray-code
98. 验证二叉搜索树3https://leetcode-cn.com/problems/validate-binary-search-tree
152. 乘积最大子数组3https://leetcode-cn.com/problems/maximum-product-subarray
384. 打乱数组3https://leetcode-cn.com/problems/shuffle-an-array
37. 解数独3https://leetcode-cn.com/problems/sudoku-solver
36. 有效的数独3https://leetcode-cn.com/problems/valid-sudoku
面试题 08.12. 八皇后3https://leetcode-cn.com/problems/eight-queens-lcci
141. 环形链表3https://leetcode-cn.com/problems/linked-list-cycle
153. 寻找旋转排序数组中的最小值3https://leetcode-cn.com/problems/find-minimum-in-rotated-sorted-array
33. 搜索旋转排序数组3https://leetcode-cn.com/problems/search-in-rotated-sorted-array
剑指 Offer 46. 把数字翻译成字符串2https://leetcode-cn.com/problems/ba-shu-zi-fan-yi-cheng-zi-fu-chuan-lcof
415. 字符串相加2https://leetcode-cn.com/problems/add-strings
986. 区间列表的交集2https://leetcode-cn.com/problems/interval-list-intersections
547. 省份数量（原朋友圈）2https://leetcode-cn.com/problems/number-of-provinces
34. 在排序数组中查找元素的第一个和最后一个位置2https://leetcode-cn.com/problems/find-first-and-last-position-of-element-in-sorted-array
142. 环形链表 II2https://leetcode-cn.com/problems/linked-list-cycle-ii
154. 寻找旋转排序数组中的最小值 II2https://leetcode-cn.com/problems/find-minimum-in-rotated-sorted-array-ii
283. 移动零2https://leetcode-cn.com/problems/move-zeroes
10. 正则表达式匹配2https://leetcode-cn.com/problems/regular-expression-matching
79. 单词搜索2https://leetcode-cn.com/problems/word-search
剑指 Offer 52. 两个链表的第一个公共节点2https://leetcode-cn.com/problems/liang-ge-lian-biao-de-di-yi-ge-gong-gong-jie-dian-lcof
76. 最小覆盖子串2https://leetcode-cn.com/problems/minimum-window-substring
449. 序列化和反序列化二叉搜索树2https://leetcode-cn.com/problems/serialize-and-deserialize-bst
300. 最长上升子序列2https://leetcode-cn.com/problems/longest-increasing-subsequence
剑指 Offer 33. 二叉搜索树的后序遍历序列2https://leetcode-cn.com/problems/er-cha-sou-suo-shu-de-hou-xu-bian-li-xu-lie-lcof
剑指 Offer 04. 二维数组中的查找2https://leetcode-cn.com/problems/er-wei-shu-zu-zhong-de-cha-zhao-lcof
剑指 Offer 51. 数组中的逆序对2https://leetcode-cn.com/problems/shu-zu-zhong-de-ni-xu-dui-lcof
877. 石子游戏2https://leetcode-cn.com/problems/stone-game
59. 螺旋矩阵 II2https://leetcode-cn.com/problems/spiral-matrix-ii
25. K 个一组翻转链表2https://leetcode-cn.com/problems/reverse-nodes-in-k-group
287. 寻找重复数2https://leetcode-cn.com/problems/find-the-duplicate-number
362. 敲击计数器2https://leetcode-cn.com/problems/design-hit-counter
119. 杨辉三角 II2https://leetcode-cn.com/problems/pascals-triangle-ii
863. 二叉树中所有距离为 K 的结点2https://leetcode-cn.com/problems/all-nodes-distance-k-in-binary-tree
1095. 山脉数组中查找目标值2https://leetcode-cn.com/problems/find-in-mountain-array
295. 数据流的中位数2https://leetcode-cn.com/problems/find-median-from-data-stream
8. 字符串转换整数 (atoi)2https://leetcode-cn.com/problems/string-to-integer-atoi
129. 求根到叶子节点数字之和2https://leetcode-cn.com/problems/sum-root-to-leaf-numbers
173. 二叉搜索树迭代器2https://leetcode-cn.com/problems/binary-search-tree-iterator
73. 矩阵置零2https://leetcode-cn.com/problems/set-matrix-zeroes
补充题12. 二叉树的下一个节点2https://mp.weixin.qq.com/s/yewlHvHSilMsrUMFIO8WAA
补充题6. 手撕堆排序2https://leetcode-cn.com/problems/sort-an-array
148. 排序链表2https://leetcode-cn.com/problems/sort-list
208. 实现 Trie (前缀树)2https://leetcode-cn.com/problems/implement-trie-prefix-tree
706. 设计哈希映射2https://leetcode-cn.com/problems/design-hashmap
160. 相交链表2https://leetcode-cn.com/problems/intersection-of-two-linked-lists
428. 序列化和反序列化 N 叉树2https://leetcode-cn.com/problems/serialize-and-deserialize-n-ary-tree
64. 最小路径和2https://leetcode-cn.com/problems/minimum-path-sum
116. 填充每个节点的下一个右侧节点指针2https://leetcode-cn.com/problems/populating-next-right-pointers-in-each-node
105. 从前序与中序遍历序列构造二叉树2https://leetcode-cn.com/problems/construct-binary-tree-from-preorder-and-inorder-traversal
40. 组合总和 II2https://leetcode-cn.com/problems/combination-sum-ii
189. 旋转数组2https://leetcode-cn.com/problems/rotate-array
84. 柱状图中最大的矩形1https://leetcode-cn.com/problems/largest-rectangle-in-histogram
120. 三角形最小路径和1https://leetcode-cn.com/problems/triangle
5. 最长回文子串1https://leetcode-cn.com/problems/longest-palindromic-substring
867. 转置矩阵1https://leetcode-cn.com/problems/transpose-matrix
78. 子集1https://leetcode-cn.com/problems/subsets
907. 子数组的最小值之和1https://leetcode-cn.com/problems/sum-of-subarray-minimums
1013. 将数组分成和相等的三个部分1https://leetcode-cn.com/problems/partition-array-into-three-parts-with-equal-sum
572. 另一个树的子树1https://leetcode-cn.com/problems/subtree-of-another-tree
704. 二分查找1https://leetcode-cn.com/problems/binary-search
171. Excel表列序号1https://leetcode-cn.com/problems/excel-sheet-column-number
150. 逆波兰表达式求值1https://leetcode-cn.com/problems/evaluate-reverse-polish-notation
767. 重构字符串1https://leetcode-cn.com/problems/reorganize-string
459. 重复的子字符串1https://leetcode-cn.com/problems/repeated-substring-pattern
973. 最接近原点的 K 个点1https://leetcode-cn.com/problems/k-closest-points-to-origin
剑指 Offer 21. 调整数组顺序使奇数位于偶数前面1https://leetcode-cn.com/problems/diao-zheng-shu-zu-shun-xu-shi-qi-shu-wei-yu-ou-shu-qian-mian-lcof
剑指 Offer 36. 二叉搜索树与双向链表1https://leetcode-cn.com/problems/er-cha-sou-suo-shu-yu-shuang-xiang-lian-biao-lcof
887. 鸡蛋掉落1https://leetcode-cn.com/problems/super-egg-drop
剑指 Offer 26. 树的子结构1https://leetcode-cn.com/problems/shu-de-zi-jie-gou-lcof
328. 奇偶链表1https://leetcode-cn.com/problems/odd-even-linked-list
137. 只出现一次的数字 II1https://leetcode-cn.com/problems/single-number-ii
155. 最小栈1https://leetcode-cn.com/problems/min-stack
1375. 灯泡开关 III1https://leetcode-cn.com/problems/bulb-switcher-iii
662. 二叉树最大宽度1https://leetcode-cn.com/problems/maximum-width-of-binary-tree
44. 通配符匹配1https://leetcode-cn.com/problems/wildcard-matching
739. 每日温度1https://leetcode-cn.com/problems/daily-temperatures
122. 买卖股票的最佳时机 II1https://leetcode-cn.com/problems/best-time-to-buy-and-sell-stock-ii
20. 有效的括号1https://leetcode-cn.com/problems/valid-parentheses
700. 二叉搜索树中的搜索1https://leetcode-cn.com/problems/search-in-a-binary-search-tree
701. 二叉搜索树中的插入操作1https://leetcode-cn.com/problems/insert-into-a-binary-search-tree
1312. 让字符串成为回文串的最少插入次数1https://leetcode-cn.com/problems/minimum-insertion-steps-to-make-a-string-palindrome
139. 单词拆分1https://leetcode-cn.com/problems/word-break
557. 反转字符串中的单词 III1https://leetcode-cn.com/problems/reverse-words-in-a-string-iii
60. 第k个排列1https://leetcode-cn.com/problems/permutation-sequence
848. 字母移位1https://leetcode-cn.com/problems/shifting-letters
569. 员工薪水中位数1https://leetcode-cn.com/problems/median-employee-salary
88. 合并两个有序数组1https://leetcode-cn.com/problems/merge-sorted-array
617. 合并二叉树1https://leetcode-cn.com/problems/merge-two-binary-trees
349. 两个数组的交集1https://leetcode-cn.com/problems/intersection-of-two-arrays
713. 乘积小于K的子数组1https://leetcode-cn.com/problems/subarray-product-less-than-k
102. 二叉树的层序遍历1https://leetcode-cn.com/problems/binary-tree-level-order-traversal
113. 路径总和 II1https://leetcode-cn.com/problems/path-sum-ii
692. 前K个高频单词1https://leetcode-cn.com/problems/top-k-frequent-words
394. 字符串解码1https://leetcode-cn.com/problems/decode-string
1155. 掷骰子的N种方法1https://leetcode-cn.com/problems/number-of-dice-rolls-with-target-sum
694. 不同岛屿的数量1https://leetcode-cn.com/problems/number-of-distinct-islands
1314. 矩阵区域和1https://leetcode-cn.com/problems/matrix-block-sum
82. 删除排序链表中的重复元素 II1https://leetcode-cn.com/problems/remove-duplicates-from-sorted-list-ii
123. 买卖股票的最佳时机 III1https://leetcode-cn.com/problems/best-time-to-buy-and-sell-stock-iii
114. 二叉树展开为链表1https://leetcode-cn.com/problems/flatten-binary-tree-to-linked-list
104. 二叉树的最大深度1https://leetcode-cn.com/problems/maximum-depth-of-binary-tree
407. 接雨水 II1https://leetcode-cn.com/problems/trapping-rain-water-ii
剑指 Offer 40. 最小的k个数1https://leetcode-cn.com/problems/zui-xiao-de-kge-shu-lcof
347. 前 K 个高频元素1https://leetcode-cn.com/problems/top-k-frequent-elements
剑指 Offer 31. 栈的压入、弹出序列1https://leetcode-cn.com/problems/zhan-de-ya-ru-dan-chu-xu-lie-lcof
29. 两数相除1https://leetcode-cn.com/problems/divide-two-integers
1356. 根据数字二进制下 1 的数目排序1https://leetcode-cn.com/problems/sort-integers-by-the-number-of-1-bits
386. 字典序排数1https://leetcode-cn.com/problems/lexicographical-numbers
311. 稀疏矩阵的乘法1https://leetcode-cn.com/problems/sparse-matrix-multiplication
166. 分数到小数1https://leetcode-cn.com/problems/fraction-to-recurring-decimal
补充题14. 阿拉伯数字转中文数字1 
21. 合并两个有序链表1https://leetcode-cn.com/problems/merge-two-sorted-lists
1358. 包含所有三种字符的子字符串数目1https://leetcode-cn.com/problems/number-of-substrings-containing-all-three-characters
剑指 Offer 53 - II. 0～n-1中缺失的数字1https://leetcode-cn.com/problems/que-shi-de-shu-zi-lcof
补充题17. 两个有序数组第k小的数1 
209. 长度最小的子数组1https://leetcode-cn.com/problems/minimum-size-subarray-sum
227. 基本计算器 II1https://leetcode-cn.com/problems/basic-calculator-ii
470. 用 Rand7() 实现 Rand10()1https://leetcode-cn.com/problems/implement-rand10-using-rand7
13. 罗马数字转整数1https://leetcode-cn.com/problems/roman-to-integer
643. 子数组最大平均数 I1https://leetcode-cn.com/problems/maximum-average-subarray-i
871. 最低加油次数1https://leetcode-cn.com/problems/minimum-number-of-refueling-stops
1615. 最大网络秩1https://leetcode-cn.com/problems/maximal-network-rank
剑指 Offer 56 - II. 数组中数字出现的次数 II1https://leetcode-cn.com/problems/shu-zu-zhong-shu-zi-chu-xian-de-ci-shu-ii-lcof
1483. 树节点的第 K 个祖先1https://leetcode-cn.com/problems/kth-ancestor-of-a-tree-node
1570. 两个稀疏向量的点积1https://leetcode-cn.com/problems/dot-product-of-two-sparse-vectors
628. 三个数的最大乘积1https://leetcode-cn.com/problems/maximum-product-of-three-numbers
145. 二叉树的后序遍历1https://leetcode-cn.com/problems/binary-tree-postorder-traversal
46. 全排列1https://leetcode-cn.com/problems/permutations
460. LFU缓存1https://leetcode-cn.com/problems/lfu-cache
785. 判断二分图1https://leetcode-cn.com/problems/is-graph-bipartite
718. 最长重复子数组1https://leetcode-cn.com/problems/maximum-length-of-repeated-subarray
242. 有效的字母异位词1https://leetcode-cn.com/problems/valid-anagram
307. 区域和检索 - 数组可修改1https://leetcode-cn.com/problems/range-sum-query-mutable
442. 数组中重复的数据1https://leetcode-cn.com/problems/find-all-duplicates-in-an-array
补充题13. 中文数字转阿拉伯数字1 
56. 合并区间1https://leetcode-cn.com/problems/merge-intervals
17. 电话号码的字母组合1https://leetcode-cn.com/problems/letter-combinations-of-a-phone-number
1143. 最长公共子序列1https://leetcode-cn.com/problems/longest-common-subsequence
179. 最大数1https://leetcode-cn.com/problems/largest-number
513. 找树左下角的值1https://leetcode-cn.com/problems/find-bottom-left-tree-value
133. 克隆图1https://leetcode-cn.com/problems/clone-graph
99. 恢复二叉搜索树1https://leetcode-cn.com/problems/recover-binary-search-tree
剑指 Offer 48. 最长不含重复字符的子字符串1https://leetcode-cn.com/problems/zui-chang-bu-han-zhong-fu-zi-fu-de-zi-zi-fu-chuan-lcof
168. Excel表列名称1https://leetcode-cn.com/problems/excel-sheet-column-title
2. 两数相加1https://leetcode-cn.com/problems/add-two-numbers
337. 打家劫舍 III1https://leetcode-cn.com/problems/house-robber-iii
518. 零钱兑换 II1https://leetcode-cn.com/problems/coin-change-2
844. 比较含退格的字符串1https://leetcode-cn.com/problems/backspace-string-compare
353. 贪吃蛇1https://leetcode-cn.com/problems/design-snake-game
198. 打家劫舍1https://leetcode-cn.com/problems/house-robber
109. 有序链表转换二叉搜索树1https://leetcode-cn.com/problems/convert-sorted-list-to-binary-search-tree
70. 爬楼梯1https://leetcode-cn.com/problems/climbing-stairs
面试题 17.24. 最大子矩阵1https://leetcode-cn.com/problems/max-submatrix-lcci
268. 缺失数字1https://leetcode-cn.com/problems/missing-number
1497. 检查数组对是否可以被 k 整除1https://leetcode-cn.com/problems/check-if-array-pairs-are-divisible-by-k
239. 滑动窗口最大值1https://leetcode-cn.com/problems/sliding-window-maximum
354. 俄罗斯套娃信封问题1https://leetcode-cn.com/problems/russian-doll-envelopes
752. 打开转盘锁1https://leetcode-cn.com/problems/open-the-lock
797. 所有可能的路径1https://leetcode-cn.com/problems/all-paths-from-source-to-target
222. 完全二叉树的节点个数1https://leetcode-cn.com/problems/count-complete-tree-nodes
322. 零钱兑换1https://leetcode-cn.com/problems/coin-change
743. 网络延迟时间1https://leetcode-cn.com/problems/network-delay-time
199. 二叉树的右视图1https://leetcode-cn.com/problems/binary-tree-right-side-view
135. 分发糖果1https://leetcode-cn.com/problems/candy
41. 缺失的第一个正数1https://leetcode-cn.com/problems/first-missing-positive
剑指 Offer 15. 二进制中1的个数1https://leetcode-cn.com/problems/er-jin-zhi-zhong-1de-ge-shu-lcof
剑指 Offer 22. 链表中倒数第k个节点1https://leetcode-cn.com/problems/lian-biao-zhong-dao-shu-di-kge-jie-dian-lcof
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Engineering & Philosophy & Life Experience - A Motorcycle rider and loving husband.