LeetCode LeetCode 个人题解, 解法基于C++ Content Title Difficulty Solution 1.Two Sum Easy 枚举/enumeration 2.Add Two Numbers Medium 链表/linked lists 3.Longest Substring Without Repeating Characters Medium dp、string、enumeration 4.Median of Two Sorted Arrays Hard sort 5.Longest Palindromic Substring Medium 枚举、回文串 6.ZigZag Conversion Medium string、模拟 7.Reverse Integer Easy 模拟、数学 8.String to Integer (atoi) Medium 模拟、string 9.Palindrome Number Easy 模拟 10.Regular Expression Matching Hard dp、正则 11.Container With Most Water Medium dp 12.Integer to Roman Medium 模拟、数学 13.Roman to Integer Easy 模拟、数学 14.Longest Common Prefix Easy string，dp 15.3Sum Medium dp 16.3Sum Closest Medium dp 17.Letter Combinations of a Phone Number Medium string、模拟、递归 18.4Sum Medium dp 19.Remove Nth Node From End of List Medium List 20.Valid Parentheses Easy stack 21.Merge Two Sorted Lists Easy merge sort 22.Generate Parentheses Medium recursion、dfs 23.Merge k Sorted Lists Hard heap sort 24.Swap Nodes in Pairs Medium recursion、dfs 25.Reverse Nodes in k-Group Hard list、模拟 26.Remove Duplicates from Sorted Array Easy 模拟、有序序列去重 27.Remove Element Easy 模拟、去掉序列中指定元素 28.Implement strStr Easy 暴力枚举/kmp 29.Divide Two Integers Medium 数学 30.Substring with Concatenation of All Words Hard string、模拟、map 31.Next Permutation medium stl or dfs 32.Long Valid Parentheses Hard 栈、括号匹配 33.Search in Rotated Sorted Array medium 二分 34.Find First and Last Position of Element in Sorted Array medium 二分 35.Search Insert Position Easy 二分 36.Valid Sudoku Medium Hash 37.Sudoku Solver Hard dfs、回溯+Hash 38.Count and Say Easy dfs、递归 39.Combination Sum Medium dfs、回溯 40.Combination Sum II Medium dfs、回溯 41.First Missing Positive Hard bucket sort/桶排 42.Trapping Rain Water Hard dp 43.Multiply Strings Medium 高精度乘法 44.Wildcard Matching Hard dp 45.Jump Game II Hard dp+贪心 46.Permutations Medium dfs、回溯 47.Permutations II Medium dfs、回溯、hash 48.Rotate Image Medium 模拟 49.Group Anagrams Medium hash 50.Pow(x, n) Medium 快速幂 1-50 51-100 101-150