原文链接: https://leetcode-cn.com/problems/longest-common-prefix 英文原文Write a function to find the longest common prefix string amongst an array of strings. If there is no common prefix, return an empty string "". Example 1: Input: strs = ["flower","flow"…

原文链接: https://leetcode-cn.com/problems/3sum 英文原文Given an integer array nums, return all the triplets [nums[i], nums[j], nums[k]] such that i != j, i != k, and j != k, and nums[i] + nums[j] + nums[k] == 0. Notice that the solution set must not contain…

原文链接: https://leetcode-cn.com/problems/letter-combinations-of-a-phone-number 英文原文Given a string containing digits from 2-9 inclusive, return all possible letter combinations that the number could represent. Return the answer in any order. A mapping o…

原文链接: https://leetcode-cn.com/problems/4sum 英文原文Given an array nums of n integers, return an array of all the unique quadruplets [nums[a], nums[b], nums[c], nums[d]] such that: 0 <= a, b, c, d < n a, b, c, and d are distinct. nums[a] + nums[b] + nums…

原文链接: https://leetcode-cn.com/problems/remove-nth-node-from-end-of-list 英文原文Given the head of a linked list, remove the nth node from the end of the list and return its head. Example 1: Input: head = [1,2,3,4,5], n = 2 Output: [1,2,3,5] Example 2: In…

原文链接: https://leetcode-cn.com/problems/valid-parentheses 英文原文Given a string s containing just the characters '(', ')', '{', '}', '[' and ']', determine if the input string is valid. An input string is valid if: Open brackets must be closed by the sam…

原文链接: https://leetcode-cn.com/problems/merge-two-sorted-lists 英文原文You are given the heads of two sorted linked lists list1 and list2. Merge the two lists in a one sorted list. The list should be made by splicing together the nodes of the first two li…

原文链接: https://leetcode-cn.com/problems/generate-parentheses 英文原文Given n pairs of parentheses, write a function to generate all combinations of well-formed parentheses. Example 1: Input: n = 3 Output: ["((()))","(()())","(())()","()(())","()()()"] Exa…

原文链接: https://leetcode-cn.com/problems/merge-k-sorted-lists 英文原文You are given an array of k linked-lists lists, each linked-list is sorted in ascending order. Merge all the linked-lists into one sorted linked-list and return it. Example 1: Input: lis…

原文链接: https://leetcode-cn.com/problems/swap-nodes-in-pairs 英文原文Given a linked list, swap every two adjacent nodes and return its head. You must solve the problem without modifying the values in the list's nodes (i.e., only nodes themselves may be cha…

原文链接: https://leetcode-cn.com/problems/reverse-nodes-in-k-group 英文原文Given a linked list, reverse the nodes of a linked list k at a time and return its modified list. k is a positive integer and is less than or equal to the length of the linked list. …

原文链接: https://leetcode-cn.com/problems/remove-duplicates-from-sorted-array 英文原文Given an integer array nums sorted in non-decreasing order, remove the duplicates in-place such that each unique element appears only once. The relative order of the eleme…

原文链接: https://leetcode-cn.com/problems/implement-strstr 英文原文Implement strStr(). Return the index of the first occurrence of needle in haystack, or -1 if needle is not part of haystack. Clarification: What should we return when needle is an empty stri…

原文链接: https://leetcode-cn.com/problems/divide-two-integers 英文原文Given two integers dividend and divisor, divide two integers without using multiplication, division, and mod operator. The integer division should truncate toward zero, which means losing…

原文链接: https://leetcode-cn.com/problems/substring-with-concatenation-of-all-words 英文原文You are given a string s and an array of strings words of the same length. Return all starting indices of substring(s) in s that is a concatenation of each word in w…

原文链接: https://leetcode-cn.com/problems/next-permutation 英文原文Implement next permutation, which rearranges numbers into the lexicographically next greater permutation of numbers. If such an arrangement is not possible, it must rearrange it as the lowes…

原文链接: https://leetcode-cn.com/problems/longest-valid-parentheses 英文原文Given a string containing just the characters '(' and ')', find the length of the longest valid (well-formed) parentheses substring. Example 1: Input: s = "(()" Output: 2 Explanatio…

原文链接: https://leetcode-cn.com/problems/search-in-rotated-sorted-array 英文原文There is an integer array nums sorted in ascending order (with distinct values). Prior to being passed to your function, nums is possibly rotated at an unknown pivot index k (1…

原文链接: https://leetcode-cn.com/problems/find-first-and-last-position-of-element-in-sorted-array 英文原文Given an array of integers nums sorted in non-decreasing order, find the starting and ending position of a given target value. If target is not found i…

原文链接: https://leetcode-cn.com/problems/search-insert-position 英文原文Given a sorted array of distinct integers and a target value, return the index if the target is found. If not, return the index where it would be if it were inserted in order. You must…

原文链接: https://leetcode-cn.com/problems/valid-sudoku 英文原文Determine if a 9 x 9 Sudoku board is valid. Only the filled cells need to be validated according to the following rules: Each row must contain the digits 1-9 without repetition. Each column must…

原文链接: https://leetcode-cn.com/problems/sudoku-solver 英文原文Write a program to solve a Sudoku puzzle by filling the empty cells. A sudoku solution must satisfy all of the following rules: Each of the digits 1-9 must occur exactly once in each row. Each …

原文链接: https://leetcode-cn.com/problems/combination-sum 英文原文Given an array of distinct integers candidates and a target integer target, return a list of all unique combinations of candidates where the chosen numbers sum to target. You may return the c…

原文链接: https://leetcode-cn.com/problems/combination-sum-ii 英文原文Given a collection of candidate numbers (candidates) and a target number (target), find all unique combinations in candidates where the candidate numbers sum to target. Each number in cand…

原文链接: https://leetcode-cn.com/problems/first-missing-positive 英文原文Given an unsorted integer array nums, return the smallest missing positive integer. You must implement an algorithm that runs in O(n) time and uses constant extra space. Example 1: Inp…

原文链接: https://leetcode-cn.com/problems/trapping-rain-water 英文原文Given n non-negative integers representing an elevation map where the width of each bar is 1, compute how much water it can trap after raining. Example 1: Input: height = [0,1,0,2,1,0,1,3…

原文链接: https://leetcode-cn.com/problems/multiply-strings 英文原文Given two non-negative integers num1 and num2 represented as strings, return the product of num1 and num2, also represented as a string. Note: You must not use any built-in BigInteger librar…

原文链接: https://leetcode-cn.com/problems/wildcard-matching 英文原文Given an input string (s) and a pattern (p), implement wildcard pattern matching with support for '?' and '*' where: '?' Matches any single character. '*' Matches any sequence of characters…

原文链接: https://leetcode-cn.com/problems/jump-game-ii 英文原文Given an array of non-negative integers nums, you are initially positioned at the first index of the array. Each element in the array represents your maximum jump length at that position. Your g…

原文链接: https://leetcode-cn.com/problems/permutations 英文原文Given an array nums of distinct integers, return all the possible permutations. You can return the answer in any order. Example 1: Input: nums = [1,2,3] Output: [[1,2,3],[1,3,2],[2,1,3],[2,3,1],…