原文链接: https://leetcode-cn.com/problems/big-countries 英文原文Table: World +-------------+---------+ | Column Name | Type | +-------------+---------+ | name | varchar | | continent | varchar | | area | int | | population | int | | gdp | int | +-----------…

原文链接: https://leetcode-cn.com/problems/classes-more-than-5-students 英文原文Table: Courses +-------------+---------+ | Column Name | Type | +-------------+---------+ | student | varchar | | class | varchar | +-------------+---------+ (student, class) is …

原文链接: https://leetcode-cn.com/problems/range-addition-ii 英文原文You are given an m x n matrix M initialized with all 0's and an array of operations ops, where ops[i] = [ai, bi] means M[x][y] should be incremented by one for all 0 <= x < ai and 0 <= y < …

原文链接: https://leetcode-cn.com/problems/minimum-index-sum-of-two-lists 英文原文Suppose Andy and Doris want to choose a restaurant for dinner, and they both have a list of favorite restaurants represented by strings. You need to help them find out their co…

原文链接: https://leetcode-cn.com/problems/non-negative-integers-without-consecutive-ones 英文原文Given a positive integer n, return the number of the integers in the range [0, n] whose binary representations do not contain consecutive ones. Example 1: Input…

原文链接: https://leetcode-cn.com/problems/human-traffic-of-stadium 英文原文Table: Stadium +---------------+---------+ | Column Name | Type | +---------------+---------+ | id | int | | visit_date | date | | people | int | +---------------+---------+ visit_da…

原文链接: https://leetcode-cn.com/problems/can-place-flowers 英文原文You have a long flowerbed in which some of the plots are planted, and some are not. However, flowers cannot be planted in adjacent plots. Given an integer array flowerbed containing 0's and…

原文链接: https://leetcode-cn.com/problems/construct-string-from-binary-tree 英文原文Given the root of a binary tree, construct a string consisting of parenthesis and integers from a binary tree with the preorder traversal way, and return it. Omit all the em…

原文链接: https://leetcode-cn.com/problems/find-duplicate-file-in-system 英文原文Given a list paths of directory info, including the directory path, and all the files with contents in this directory, return all the duplicate files in the file system in terms…

原文链接: https://leetcode-cn.com/problems/valid-triangle-number 英文原文Given an integer array nums, return the number of triplets chosen from the array that can make triangles if we take them as side lengths of a triangle. Example 1: Input: nums = [2,2,3,4…

原文链接: https://leetcode-cn.com/problems/merge-two-binary-trees 英文原文You are given two binary trees root1 and root2. Imagine that when you put one of them to cover the other, some nodes of the two trees are overlapped while the others are not. You need …

原文链接: https://leetcode-cn.com/problems/not-boring-movies 英文原文Table: Cinema +----------------+----------+ | Column Name | Type | +----------------+----------+ | id | int | | movie | varchar | | description | varchar | | rating | float | +-------------…

原文链接: https://leetcode-cn.com/problems/task-scheduler 英文原文Given a characters array tasks, representing the tasks a CPU needs to do, where each letter represents a different task. Tasks could be done in any order. Each task is done in one unit of time…

原文链接: https://leetcode-cn.com/problems/add-one-row-to-tree 英文原文Given the root of a binary tree and two integers val and depth, add a row of nodes with value val at the given depth depth. Note that the root node is at depth 1. The adding rule is: Give…

原文链接: https://leetcode-cn.com/problems/swap-salary 英文原文Table: Salary +-------------+----------+ | Column Name | Type | +-------------+----------+ | id | int | | name | varchar | | sex | ENUM | | salary | int | +-------------+----------+ id is the pri…

原文链接: https://leetcode-cn.com/problems/maximum-product-of-three-numbers 英文原文Given an integer array nums, find three numbers whose product is maximum and return the maximum product. Example 1: Input: nums = [1,2,3] Output: 6 Example 2: Input: nums = […

原文链接: https://leetcode-cn.com/problems/k-inverse-pairs-array 英文原文For an integer array nums, an inverse pair is a pair of integers [i, j] where 0 <= i < j < nums.length and nums[i] > nums[j]. Given two integers n and k, return the number of different …

原文链接: https://leetcode-cn.com/problems/course-schedule-iii 英文原文There are n different online courses numbered from 1 to n. You are given an array courses where courses[i] = [durationi, lastDayi] indicate that the ith course should be taken continuousl…

原文链接: https://leetcode-cn.com/problems/smallest-range-covering-elements-from-k-lists 英文原文You have k lists of sorted integers in non-decreasing order. Find the smallest range that includes at least one number from each of the k lists. We define the ra…

原文链接: https://leetcode-cn.com/problems/sum-of-square-numbers 英文原文Given a non-negative integer c, decide whether there're two integers a and b such that a2 + b2 = c. Example 1: Input: c = 5 Output: true Explanation: 1 * 1 + 2 * 2 = 5 Example 2: Input:…

原文链接: https://leetcode-cn.com/problems/exclusive-time-of-functions 英文原文On a single-threaded CPU, we execute a program containing n functions. Each function has a unique ID between 0 and n-1. Function calls are stored in a call stack: when a function …

原文链接: https://leetcode-cn.com/problems/shopping-offers 英文原文In LeetCode Store, there are n items to sell. Each item has a price. However, there are some special offers, and a special offer consists of one or more different kinds of items with a sale p…

原文链接: https://leetcode-cn.com/problems/decode-ways-ii 英文原文A message containing letters from A-Z can be encoded into numbers using the following mapping: 'A' -> "1" 'B' -> "2" ... 'Z' -> "26" To decode an encoded message, all the digits must be groupe…

原文链接: https://leetcode-cn.com/problems/solve-the-equation 英文原文Solve a given equation and return the value of 'x' in the form of a string "x=#value". The equation contains only '+', '-' operation, the variable 'x' and its coefficient. You should retur…

原文链接: https://leetcode-cn.com/problems/maximum-average-subarray-i 英文原文You are given an integer array nums consisting of n elements, and an integer k. Find a contiguous subarray whose length is equal to k that has the maximum average value and return …

原文链接: https://leetcode-cn.com/problems/set-mismatch 英文原文You have a set of integers s, which originally contains all the numbers from 1 to n. Unfortunately, due to some error, one of the numbers in s got duplicated to another number in the set, which …

原文链接: https://leetcode-cn.com/problems/maximum-length-of-pair-chain 英文原文You are given an array of n pairs pairs where pairs[i] = [lefti, righti] and lefti < righti. A pair p2 = [c, d] follows a pair p1 = [a, b] if b < c. A chain of pairs can be forme…

原文链接: https://leetcode-cn.com/problems/palindromic-substrings 英文原文Given a string s, return the number of palindromic substrings in it. A string is a palindrome when it reads the same backward as forward. A substring is a contiguous sequence of charac…

原文链接: https://leetcode-cn.com/problems/replace-words 英文原文In English, we have a concept called root, which can be followed by some other word to form another longer word - let's call this word successor. For example, when the root "an" is followed by …

原文链接: https://leetcode-cn.com/problems/2-keys-keyboard 英文原文There is only one character 'A' on the screen of a notepad. You can perform two operations on this notepad for each step: Copy All: You can copy all the characters present on the screen (a pa…