原文链接: https://leetcode-cn.com/problems/number-of-wonderful-substrings 英文原文A wonderful string is a string where at most one letter appears an odd number of times. For example, "ccjjc" and "abab" are wonderful, but "ab" is not. Given a string word that…

原文链接: https://leetcode-cn.com/problems/find-a-peak-element-ii 英文原文A peak element in a 2D grid is an element that is strictly greater than all of its adjacent neighbors to the left, right, top, and bottom. Given a 0-indexed m x n matrix mat where no t…

原文链接: https://leetcode-cn.com/problems/build-array-from-permutation 英文原文Given a zero-based permutation nums (0-indexed), build an array ans of the same length where ans[i] = nums[nums[i]] for each 0 <= i < nums.length and return it. A zero-based perm…

原文链接: https://leetcode-cn.com/problems/eliminate-maximum-number-of-monsters 英文原文You are playing a video game where you are defending your city from a group of n monsters. You are given a 0-indexed integer array dist of size n, where dist[i] is the in…

原文链接: https://leetcode-cn.com/problems/count-good-numbers 英文原文A digit string is good if the digits (0-indexed) at even indices are even and the digits at odd indices are prime (2, 3, 5, or 7). For example, "2582" is good because the digits (2 and 8) …

原文链接: https://leetcode-cn.com/problems/longest-common-subpath 英文原文There is a country of n cities numbered from 0 to n - 1. In this country, there is a road connecting every pair of cities. There are m friends numbered from 0 to m - 1 who are travelin…

原文链接: https://leetcode-cn.com/problems/check-if-all-characters-have-equal-number-of-occurrences 英文原文Given a string s, return true if s is a good string, or false otherwise. A string s is good if all the characters that appear in s have the same numbe…

原文链接: https://leetcode-cn.com/problems/the-number-of-the-smallest-unoccupied-chair 英文原文There is a party where n friends numbered from 0 to n - 1 are attending. There is an infinite number of chairs in this party that are numbered from 0 to infinity. …

原文链接: https://leetcode-cn.com/problems/describe-the-painting 英文原文There is a long and thin painting that can be represented by a number line. The painting was painted with multiple overlapping segments where each segment was painted with a unique colo…

原文链接: https://leetcode-cn.com/problems/unique-length-3-palindromic-subsequences 英文原文Given a string s, return the number of unique palindromes of length three that are a subsequence of s. Note that even if there are multiple ways to obtain the same su…

原文链接: https://leetcode-cn.com/problems/merge-bsts-to-create-single-bst 英文原文You are given n BST (binary search tree) root nodes for n separate BSTs stored in an array trees (0-indexed). Each BST in trees has at most 3 nodes, and no two roots have the …

原文链接: https://leetcode-cn.com/problems/painting-a-grid-with-three-different-colors 英文原文You are given two integers m and n. Consider an m x n grid where each cell is initially white. You can paint each cell red, green, or blue. All cells must be paint…

原文链接: https://leetcode-cn.com/problems/add-minimum-number-of-rungs 英文原文You are given a strictly increasing integer array rungs that represents the height of rungs on a ladder. You are currently on the floor at height 0, and you want to reach the last…

原文链接: https://leetcode-cn.com/problems/maximum-number-of-points-with-cost 英文原文You are given an m x n integer matrix points (0-indexed). Starting with 0 points, you want to maximize the number of points you can get from the matrix. To gain points, you…

原文链接: https://leetcode-cn.com/problems/maximum-genetic-difference-query 英文原文There is a rooted tree consisting of n nodes numbered 0 to n - 1. Each node's number denotes its unique genetic value (i.e. the genetic value of node x is x). The genetic dif…

原文链接: https://leetcode-cn.com/problems/sum-of-digits-of-string-after-convert 英文原文You are given a string s consisting of lowercase English letters, and an integer k. First, convert s into an integer by replacing each letter with its position in the al…

原文链接: https://leetcode-cn.com/problems/largest-number-after-mutating-substring 英文原文You are given a string num, which represents a large integer. You are also given a 0-indexed integer array change of length 10 that maps each digit 0-9 to another digi…

原文链接: https://leetcode-cn.com/problems/maximum-compatibility-score-sum 英文原文There is a survey that consists of n questions where each question's answer is either 0 (no) or 1 (yes). The survey was given to m students numbered from 0 to m - 1 and m ment…

原文链接: https://leetcode-cn.com/problems/delete-duplicate-folders-in-system 英文原文Due to a bug, there are many duplicate folders in a file system. You are given a 2D array paths, where paths[i] is an array representing an absolute path to the ith folder …

原文链接: https://leetcode-cn.com/problems/check-if-move-is-legal 英文原文You are given a 0-indexed 8 x 8 grid board, where board[r][c] represents the cell (r, c) on a game board. On the board, free cells are represented by '.', white cells are represented b…

原文链接: https://leetcode-cn.com/problems/three-divisors 英文原文Given an integer n, return true if n has exactly three positive divisors. Otherwise, return false. An integer m is a divisor of n if there exists an integer k such that n = k * m. Example 1: I…

原文链接: https://leetcode-cn.com/problems/maximum-number-of-weeks-for-which-you-can-work 英文原文There are n projects numbered from 0 to n - 1. You are given an integer array milestones where each milestones[i] denotes the number of milestones the ith proje…

原文链接: https://leetcode-cn.com/problems/count-number-of-special-subsequences 英文原文A sequence is special if it consists of a positive number of 0s, followed by a positive number of 1s, then a positive number of 2s. For example, [0,1,2] and [0,0,1,1,1,2]…

原文链接: https://leetcode-cn.com/problems/array-with-elements-not-equal-to-average-of-neighbors 英文原文You are given a 0-indexed array nums of distinct integers. You want to rearrange the elements in the array such that every element in the rearranged arra…

原文链接: https://leetcode-cn.com/problems/minimum-time-to-type-word-using-special-typewriter 英文原文There is a special typewriter with lowercase English letters 'a' to 'z' arranged in a circle with a pointer. A character can only be typed if the pointer is…

原文链接: https://leetcode-cn.com/problems/maximum-matrix-sum 英文原文You are given an n x n integer matrix. You can do the following operation any number of times: Choose any two adjacent elements of matrix and multiply each of them by -1. Two elements are …

原文链接: https://leetcode-cn.com/problems/number-of-ways-to-arrive-at-destination 英文原文You are in a city that consists of n intersections numbered from 0 to n - 1 with bi-directional roads between some intersections. The inputs are generated such that yo…

原文链接: https://leetcode-cn.com/problems/number-of-ways-to-separate-numbers 英文原文You wrote down many positive integers in a string called num. However, you realized that you forgot to add commas to seperate the different numbers. You remember that the l…

原文链接: https://leetcode-cn.com/problems/check-if-string-is-a-prefix-of-array 英文原文Given a string s and an array of strings words, determine whether s is a prefix string of words. A string s is a prefix string of words if s can be made by concatenating …

原文链接: https://leetcode-cn.com/problems/remove-stones-to-minimize-the-total 英文原文You are given a 0-indexed integer array piles, where piles[i] represents the number of stones in the ith pile, and an integer k. You should apply the following operation e…