# 后端
|题目|出现次数|链接|
|-|-|-|
|206. 反转链表|15|https://leetcode-cn.com/problems/reverse-linked-list|
|160. 相交链表|8|https://leetcode-cn.com/problems/intersection-of-two-linked-lists|
|补充题4. 手撕快速排序|7||
|146. LRU缓存机制|7|https://leetcode-cn.com/problems/lru-cache|
|21. 合并两个有序链表|7|https://leetcode-cn.com/problems/merge-two-sorted-lists|
|215. 数组中的第K个最大元素|7|https://leetcode-cn.com/problems/kth-largest-element-in-an-array|
|88. 合并两个有序数组|6|https://leetcode-cn.com/problems/merge-sorted-array|
|141. 环形链表|5|https://leetcode-cn.com/problems/linked-list-cycle|
|92. 反转链表 II|5|https://leetcode-cn.com/problems/reverse-linked-list-ii|
|151. 翻转字符串里的单词|5|https://leetcode-cn.com/problems/reverse-words-in-a-string|
|2. 两数相加|5|https://leetcode-cn.com/problems/add-two-numbers|
|3. 无重复字符的最长子串|5|https://leetcode-cn.com/problems/longest-substring-without-repeating-characters|
|155. 最小栈|4|https://leetcode-cn.com/problems/min-stack|
|144. 二叉树的前序遍历|4|https://leetcode-cn.com/problems/binary-tree-preorder-traversal|
|136. 只出现一次的数字|4|https://leetcode-cn.com/problems/single-number|
|34. 在排序数组中查找元素的第一个和最后一个位置|4|https://leetcode-cn.com/problems/find-first-and-last-position-of-element-in-sorted-array|
|20. 有效的括号|4|https://leetcode-cn.com/problems/valid-parentheses|
|148. 排序链表|4|https://leetcode-cn.com/problems/sort-list|
|24. 两两交换链表中的节点|4|https://leetcode-cn.com/problems/swap-nodes-in-pairs|
|415. 字符串相加|4|https://leetcode-cn.com/problems/add-strings|
|142. 环形链表 II|3|https://leetcode-cn.com/problems/linked-list-cycle-ii|
|46. 全排列|3|https://leetcode-cn.com/problems/permutations|
|剑指 Offer 10- II. 青蛙跳台阶问题|3|https://leetcode-cn.com/problems/qing-wa-tiao-tai-jie-wen-ti-lcof|
|剑指 Offer 22. 链表中倒数第k个节点|3|https://leetcode-cn.com/problems/lian-biao-zhong-dao-shu-di-kge-jie-dian-lcof|
|150. 逆波兰表达式求值|3|https://leetcode-cn.com/problems/evaluate-reverse-polish-notation|
|94. 二叉树的中序遍历|3|https://leetcode-cn.com/problems/binary-tree-inorder-traversal|
|128. 最长连续序列|3|https://leetcode-cn.com/problems/longest-consecutive-sequence|
|补充题8. 计算数组的小和|3|https://mp.weixin.qq.com/s/0ih4W6nawzFUPSj3GOnYTQ|
|121. 买卖股票的最佳时机|3|https://leetcode-cn.com/problems/best-time-to-buy-and-sell-stock|
|补充题5. 手撕归并排序|3||
|69. x 的平方根|3|https://leetcode-cn.com/problems/sqrtx|
|103. 二叉树的锯齿形层次遍历|3|https://leetcode-cn.com/problems/binary-tree-zigzag-level-order-traversal|
|102. 二叉树的层序遍历|3|https://leetcode-cn.com/problems/binary-tree-level-order-traversal|
|剑指 Offer 51. 数组中的逆序对|3|https://leetcode-cn.com/problems/shu-zu-zhong-de-ni-xu-dui-lcof|
|剑指 Offer 21. 调整数组顺序使奇数位于偶数前面|3|https://leetcode-cn.com/problems/diao-zheng-shu-zu-shun-xu-shi-qi-shu-wei-yu-ou-shu-qian-mian-lcof|
|76. 最小覆盖子串|3|https://leetcode-cn.com/problems/minimum-window-substring|
|15. 三数之和|2|https://leetcode-cn.com/problems/3sum|
|145. 二叉树的后序遍历|2|https://leetcode-cn.com/problems/binary-tree-postorder-traversal|
|543. 二叉树的直径|2|https://leetcode-cn.com/problems/diameter-of-binary-tree|
|845. 数组中的最长山脉|2|https://leetcode-cn.com/problems/longest-mountain-in-array|
|剑指 Offer 18. 删除链表的节点|2|https://leetcode-cn.com/problems/shan-chu-lian-biao-de-jie-dian-lcof|
|1143. 最长公共子序列|2|https://leetcode-cn.com/problems/longest-common-subsequence|
|剑指 Offer 19. 正则表达式匹配|2|https://leetcode-cn.com/problems/zheng-ze-biao-da-shi-pi-pei-lcof|
|509. 斐波那契数|2|https://leetcode-cn.com/problems/fibonacci-number|
|226. 翻转二叉树|2|https://leetcode-cn.com/problems/invert-binary-tree|
|93. 复原IP地址|2|https://leetcode-cn.com/problems/restore-ip-addresses|
|1047. 删除字符串中的所有相邻重复项|2|https://leetcode-cn.com/problems/remove-all-adjacent-duplicates-in-string|
|43. 字符串相乘|2|https://leetcode-cn.com/problems/multiply-strings|
|113. 路径总和 II|2|https://leetcode-cn.com/problems/path-sum-ii|
|718. 最长重复子数组|2|https://leetcode-cn.com/problems/maximum-length-of-repeated-subarray|
|剑指 Offer 55 - I. 二叉树的深度|2|https://leetcode-cn.com/problems/er-cha-shu-de-shen-du-lcof|
|78. 子集|2|https://leetcode-cn.com/problems/subsets|
|498. 对角线遍历|2|https://leetcode-cn.com/problems/diagonal-traverse|
|122. 买卖股票的最佳时机 II|2|https://leetcode-cn.com/problems/best-time-to-buy-and-sell-stock-ii|
|剑指 Offer 36. 二叉搜索树与双向链表|2|https://leetcode-cn.com/problems/er-cha-sou-suo-shu-yu-shuang-xiang-lian-biao-lcof|
|200. 岛屿数量|2|https://leetcode-cn.com/problems/number-of-islands|
|33. 搜索旋转排序数组|2|https://leetcode-cn.com/problems/search-in-rotated-sorted-array|
|54. 螺旋矩阵|2|https://leetcode-cn.com/problems/spiral-matrix|
|225. 用队列实现栈|2|https://leetcode-cn.com/problems/implement-stack-using-queues|
|23. 合并K个排序链表|2|https://leetcode-cn.com/problems/merge-k-sorted-lists|
|104. 二叉树的最大深度|2|https://leetcode-cn.com/problems/maximum-depth-of-binary-tree|
|318. 最大单词长度乘积|1|https://leetcode-cn.com/problems/maximum-product-of-word-lengths|
|321. 拼接最大数|1|https://leetcode-cn.com/problems/create-maximum-number|
|面试题 17.01. 不用加号的加法|1|https://leetcode-cn.com/problems/add-without-plus-lcci|
|468. 验证IP地址|1|https://leetcode-cn.com/problems/validate-ip-address|
|16. 最接近的三数之和|1|https://leetcode-cn.com/problems/3sum-closest|
|239. 滑动窗口最大值|1|https://leetcode-cn.com/problems/sliding-window-maximum|
|470. 用 Rand7() 实现 Rand10()|1|https://leetcode-cn.com/problems/implement-rand10-using-rand7|
|8. 字符串转换整数 (atoi)|1|https://leetcode-cn.com/problems/string-to-integer-atoi|
|剑指 Offer 24. 反转链表|1|https://leetcode-cn.com/problems/fan-zhuan-lian-biao-lcof|
|67. 二进制求和|1|https://leetcode-cn.com/problems/add-binary|
|450. 删除二叉搜索树中的节点|1|https://leetcode-cn.com/problems/delete-node-in-a-bst|
|322. 零钱兑换|1|https://leetcode-cn.com/problems/coin-change|
|220. 存在重复元素 III|1|https://leetcode-cn.com/problems/contains-duplicate-iii|
|剑指 Offer 04. 二维数组中的查找|1|https://leetcode-cn.com/problems/er-wei-shu-zu-zhong-de-cha-zhao-lcof|
|48. 旋转图像|1|https://leetcode-cn.com/problems/rotate-image|
|337. 打家劫舍 III|1|https://leetcode-cn.com/problems/house-robber-iii|
|191. 位1的个数|1|https://leetcode-cn.com/problems/number-of-1-bits|
|22. 括号生成|1|https://leetcode-cn.com/problems/generate-parentheses|
|5. 最长回文子串|1|https://leetcode-cn.com/problems/longest-palindromic-substring|
|224. 基本计算器|1|https://leetcode-cn.com/problems/basic-calculator|
|701. 二叉搜索树中的插入操作|1|https://leetcode-cn.com/problems/insert-into-a-binary-search-tree|
|111. 二叉树的最小深度|1|https://leetcode-cn.com/problems/minimum-depth-of-binary-tree|
|110. 平衡二叉树|1|https://leetcode-cn.com/problems/balanced-binary-tree|
|210. 课程表 II|1|https://leetcode-cn.com/problems/course-schedule-ii|
|480. 滑动窗口中位数|1|https://leetcode-cn.com/problems/sliding-window-median|
|137. 只出现一次的数字 II|1|https://leetcode-cn.com/problems/single-number-ii|
|剑指 Offer 41. 数据流中的中位数|1|https://leetcode-cn.com/problems/shu-ju-liu-zhong-de-zhong-wei-shu-lcof|
|42. 接雨水|1|https://leetcode-cn.com/problems/trapping-rain-water|
|82. 删除排序链表中的重复元素 II|1|https://leetcode-cn.com/problems/remove-duplicates-from-sorted-list-ii|
|230. 二叉搜索树中第K小的元素|1|https://leetcode-cn.com/problems/kth-smallest-element-in-a-bst|
|剑指 Offer 10- I. 斐波那契数列|1|https://leetcode-cn.com/problems/fei-bo-na-qi-shu-lie-lcof|
|169. 多数元素|1|https://leetcode-cn.com/problems/majority-element|
|59. 螺旋矩阵 II|1|https://leetcode-cn.com/problems/spiral-matrix-ii|
|74. 搜索二维矩阵|1|https://leetcode-cn.com/problems/search-a-2d-matrix|
|236. 二叉树的最近公共祖先|1|https://leetcode-cn.com/problems/lowest-common-ancestor-of-a-binary-tree|
|1. 两数之和|1|https://leetcode-cn.com/problems/two-sum|
|75. 颜色分类|1|https://leetcode-cn.com/problems/sort-colors|
|207. 课程表|1|https://leetcode-cn.com/problems/course-schedule|
|64. 最小路径和|1|https://leetcode-cn.com/problems/minimum-path-sum|
|1156. 单字符重复子串的最大长度|1|https://leetcode-cn.com/problems/swap-for-longest-repeated-character-substring|
|剑指 Offer 43. 1～n整数中1出现的次数|1|https://leetcode-cn.com/problems/1nzheng-shu-zhong-1chu-xian-de-ci-shu-lcof|
|14. 最长公共前缀|1|https://leetcode-cn.com/problems/longest-common-prefix|
|面试题 16.06. 最小差|1|https://leetcode-cn.com/problems/smallest-difference-lcci|
|1493. 删掉一个元素以后全为 1 的最长子数组|1|https://leetcode-cn.com/problems/longest-subarray-of-1s-after-deleting-one-element|
|剑指 Offer 09. 用两个栈实现队列|1|https://leetcode-cn.com/problems/yong-liang-ge-zhan-shi-xian-dui-lie-lcof|
|1027. 最长等差数列|1|https://leetcode-cn.com/problems/longest-arithmetic-subsequence|
|1464. 数组中两元素的最大乘积|1|https://leetcode-cn.com/problems/maximum-product-of-two-elements-in-an-array|
|235. 二叉搜索树的最近公共祖先|1|https://leetcode-cn.com/problems/lowest-common-ancestor-of-a-binary-search-tree|
|204. 计数质数|1|https://leetcode-cn.com/problems/count-primes|
|83. 删除排序链表中的重复元素|1|https://leetcode-cn.com/problems/remove-duplicates-from-sorted-list|
|958. 二叉树的完全性检验|1|https://leetcode-cn.com/problems/check-completeness-of-a-binary-tree|
|312. 戳气球|1|https://leetcode-cn.com/problems/burst-balloons|
|剑指 Offer 25. 合并两个排序的链表|1|https://leetcode-cn.com/problems/he-bing-liang-ge-pai-xu-de-lian-biao-lcof|
|9. 回文数|1|https://leetcode-cn.com/problems/palindrome-number|
|25. K 个一组翻转链表|1|https://leetcode-cn.com/problems/reverse-nodes-in-k-group|
|199. 二叉树的右视图|1|https://leetcode-cn.com/problems/binary-tree-right-side-view|
|240. 搜索二维矩阵 II|1|https://leetcode-cn.com/problems/search-a-2d-matrix-ii|
|1312. 让字符串成为回文串的最少插入次数|1|https://leetcode-cn.com/problems/minimum-insertion-steps-to-make-a-string-palindrome|
|6. Z 字形变换|1|https://leetcode-cn.com/problems/zigzag-conversion|
|189. 旋转数组|1|https://leetcode-cn.com/problems/rotate-array|
|19. 删除链表的倒数第N个节点|1|https://leetcode-cn.com/problems/remove-nth-node-from-end-of-list|
|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|
|572. 另一个树的子树|1|https://leetcode-cn.com/problems/subtree-of-another-tree|
|704. 二分查找|1|https://leetcode-cn.com/problems/binary-search|
|238. 除自身以外数组的乘积|1|https://leetcode-cn.com/problems/product-of-array-except-self|
|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|
|138. 复制带随机指针的链表|1|https://leetcode-cn.com/problems/copy-list-with-random-pointer|
|剑指 Offer 32 - III. 从上到下打印二叉树 III|1|https://leetcode-cn.com/problems/cong-shang-dao-xia-da-yin-er-cha-shu-iii-lcof|
|129. 求根到叶子节点数字之和|1|https://leetcode-cn.com/problems/sum-root-to-leaf-numbers|
|101. 对称二叉树|1|https://leetcode-cn.com/problems/symmetric-tree|
|540. 有序数组中的单一元素|1|https://leetcode-cn.com/problems/single-element-in-a-sorted-array|
|剑指 Offer 12. 矩阵中的路径|1|https://leetcode-cn.com/problems/ju-zhen-zhong-de-lu-jing-lcof|
|208. 实现 Trie (前缀树)|1|https://leetcode-cn.com/problems/implement-trie-prefix-tree|
|剑指 Offer 40. 最小的k个数|1|https://leetcode-cn.com/problems/zui-xiao-de-kge-shu-lcof|
|40. 组合总和 II|1|https://leetcode-cn.com/problems/combination-sum-ii|