# 目录

## 目录

Number 题号 Problems 题目 Difficulty 难度 Topics(Tags) 标签 1 Two Sum 两数之和等于一个输入的数 Easy Array, Hash Table 2 Add TwoNumbers 两个链表相加 Medium Linked List, Math 3 Longest Substring Without Repeating Characters 子字符串的最大不重复长度 Medium Hash Table, Two Pointers, String 4 Median of Two Sorted Arrays两个数组的中位数 Hard Array, Binary Search, Divide and Conquer 5 Longest Palindromic Substring 最长回文子字符串 Medium String, Dynamic Programming 6 ZigZag Conversion 之子形转换字符串 Medium String 7 Reverse Integer 翻转整数 Easy Math 8 String to Integer Atoi 把字符串转换成整数 Medium String, Math 9 Palindrome Number 验证回文数字 Easy Math 10 Regular Expression Matching 正则表达式匹配 Hard String, Dynamic Programming, Backtracking 11 Container With Most Water 装最多水的容器 Medium Array, Hash Table 12 Integer to Roman 整数转罗马数字 Medium String, Math 13 Roman to Integer 罗马数字转化成整数 Easy String, Math 14 Longest Common Prefix 最长共同前缀 Easy String 15 3Sum 三数之和 Medium Array, Two Pointers 16 3Sum Closest 最近三数之和 Medium Array, Two Pointers 17 Letter Combinations of a Phone Number 电话号码的字母组合 Medium String, Backtracking, DFS 18 4Sum 四数之和 Medium Array, Hash Table, Two Pointers 19 Remove Nth Node From End of List 移除链表倒数第N个节点 Medium Linked List, Two Pointers 20 Valid Parentheses 验证括号 Easy String, Stack 21 Merge Two Sorted Lists 混合插入有序链表 Easy Linked List 22 Generate Parentheses 生成括号 Medium String, Backtracking, DFS 23 Merge K Sorted Lists 合并k个有序链表 Hard Linked List, Divide and Conquer, Heap 24 Swap Nodes in Pairs 成对交换节点 Medium Linked List 25 Reverse Nodes in K Group 每k个一组翻转链表 Hard Linked List 26 Remove Duplicates From Sorted Array 有序数组中去除重复项 Easy Array, Two Pointers 27 Remove Element 移除元素 Easy Array, Two Pointers 28 Implement strStr() 实现strStr()函数 Easy Two Pointers, String 29 Divide Two Integers 两数相除 Medium Math , Binary Search 30 Substring With Concatenation of All Words 串联所有单词的子串 Hard Hash Table, Two Pointers, String 31 Next Permutation 下一个排列 Medium Array 32 Longest Valid Parentheses 最长有效括号 Hard String, Dynamic Programming 33 Search in Rotated Sorted Array 在旋转有序数组中搜索 Medium Array, Binary Search 34 Search for a Range 搜索一个范围 Medium Array, Binary Search 35 Search Insert Position 搜索插入位置 Easy Array, Binary Search 36 Valid Sudoku 验证数独 Medium Hash Table 37 Sudoku Solver 求数独的一个解 Hard Backtracking,Hash Table 38 Count and Say 计数和读法 Easy String 39 Combination Sum 组合之和 Medium Array, Backtracking 40 Combination Sum II 组合之和之二 Medium Array, Backtracking 41 First Missing Positive 首个缺失的正数 Hard Array 42 Trapping Rain Water 收集雨水 Hard Array, Two Pointers, Stack 43 Multiply Strings 字符串相乘 Medium String, Math 44 Wildcard Matching 通配符匹配 Hard Math, Dynamic Programming, Backtracking, Greedy 45 Jump Game 2 跳跃游戏2 Hard Array, Greedy 46 Permutations 全排列 Medium Backtracking 47 PermutationsII 全排列2 Medium Backtracking 48 Rotate Image 旋转图像 Medium Array 49 Group Anagrams 群组错位词 Medium String,Hash Table 50 Pow(x, n) 求x的n次方 Medium Math, Binary Search 51 N Queens N皇后问题 Hard Backtracking 52 N Queens II N皇后问题之二 Hard Backtracking 146 LRU Cache 最近最少使用置换缓存器 Hard Design