原文链接: https://leetcode-cn.com/problems/find-and-replace-pattern 英文原文Given a list of strings words and a string pattern, return a list of words[i] that match pattern. You may return the answer in any order. A word matches the pattern if there exists a…

原文链接: https://leetcode-cn.com/problems/sum-of-subsequence-widths 英文原文The width of a sequence is the difference between the maximum and minimum elements in the sequence. Given an array of integers nums, return the sum of the widths of all the non-empt…

原文链接: https://leetcode-cn.com/problems/surface-area-of-3d-shapes 英文原文You are given an n x n grid where you have placed some 1 x 1 x 1 cubes. Each value v = grid[i][j] represents a tower of v cubes placed on top of cell (i, j). After placing these cub…

原文链接: https://leetcode-cn.com/problems/groups-of-special-equivalent-strings 英文原文You are given an array of strings of the same length words. In one move, you can swap any two even indexed characters or any two odd indexed characters of a string words[…

原文链接: https://leetcode-cn.com/problems/maximum-frequency-stack 英文原文Design a stack-like data structure to push elements to the stack and pop the most frequent element from the stack. Implement the FreqStack class: FreqStack() constructs an empty frequ…

原文链接: https://leetcode-cn.com/problems/all-possible-full-binary-trees 英文原文Given an integer n, return a list of all possible full binary trees with n nodes. Each node of each tree in the answer must have Node.val == 0. Each element of the answer is th…

原文链接: https://leetcode-cn.com/problems/increasing-order-search-tree 英文原文Given the root of a binary search tree, rearrange the tree in in-order so that the leftmost node in the tree is now the root of the tree, and every node has no left child and onl…

原文链接: https://leetcode-cn.com/problems/bitwise-ors-of-subarrays 英文原文We have an array arr of non-negative integers. For every (contiguous) subarray sub = [arr[i], arr[i + 1], ..., arr[j]] (with i <= j), we take the bitwise OR of all the elements in su…

原文链接: https://leetcode-cn.com/problems/orderly-queue 英文原文You are given a string s and an integer k. You can choose one of the first k letters of s and append it at the end of the string.. Return the lexicographically smallest string you could have af…

原文链接: https://leetcode-cn.com/problems/rle-iterator 英文原文We can use run-length encoding (i.e., RLE) to encode a sequence of integers. In a run-length encoded array of even length encoding (0-indexed), for all even i, encoding[i] tells us the number of…

原文链接: https://leetcode-cn.com/problems/online-stock-span 英文原文Design an algorithm that collects daily price quotes for some stock and returns the span of that stock's price for the current day. The span of the stock's price today is defined as the max…

原文链接: https://leetcode-cn.com/problems/numbers-at-most-n-given-digit-set 英文原文Given an array of digits which is sorted in non-decreasing order. You can write numbers using each digits[i] as many times as we want. For example, if digits = ['1','3','5']…

原文链接: https://leetcode-cn.com/problems/valid-permutations-for-di-sequence 英文原文You are given a string s of length n where s[i] is either: 'D' means decreasing, or 'I' means increasing. A permutation perm of n + 1 integers of all the integers in the ra…

原文链接: https://leetcode-cn.com/problems/sort-array-by-parity 英文原文Given an integer array nums, move all the even integers at the beginning of the array followed by all the odd integers. Return any array that satisfies this condition. Example 1: Input: …

原文链接: https://leetcode-cn.com/problems/fruit-into-baskets 英文原文You are visiting a farm that has a single row of fruit trees arranged from left to right. The trees are represented by an integer array fruits where fruits[i] is the type of fruit the ith …

原文链接: https://leetcode-cn.com/problems/super-palindromes 英文原文Let's say a positive integer is a super-palindrome if it is a palindrome, and it is also the square of a palindrome. Given two positive integers left and right represented as strings, retur…

原文链接: https://leetcode-cn.com/problems/smallest-range-i 英文原文You are given an integer array nums and an integer k. In one operation, you can choose any index i where 0 <= i < nums.length and change nums[i] to nums[i] + x where x is an integer from the…

原文链接: https://leetcode-cn.com/problems/smallest-range-ii 英文原文You are given an integer array nums and an integer k. For each index i where 0 <= i < nums.length, change nums[i] to be either nums[i] + k or nums[i] - k. The score of nums is the differenc…

原文链接: https://leetcode-cn.com/problems/snakes-and-ladders 英文原文You are given an n x n integer matrix board where the cells are labeled from 1 to n2 in a Boustrophedon style starting from the bottom left of the board (i.e. board[n - 1][0]) and alternat…

原文链接: https://leetcode-cn.com/problems/online-election 英文原文You are given two integer arrays persons and times. In an election, the ith vote was cast for persons[i] at time times[i]. For each query at a time t, find the person that was leading the ele…

原文链接: https://leetcode-cn.com/problems/cat-and-mouse 英文原文A game on an undirected graph is played by two players, Mouse and Cat, who alternate turns. The graph is given as follows: graph[a] is a list of all nodes b such that ab is an edge of the graph…

原文链接: https://leetcode-cn.com/problems/sort-an-array 英文原文Given an array of integers nums, sort the array in ascending order. Example 1: Input: nums = [5,2,3,1] Output: [1,2,3,5] Example 2: Input: nums = [5,1,1,2,0,0] Output: [0,0,1,1,2,5] Constraints…

原文链接: https://leetcode-cn.com/problems/x-of-a-kind-in-a-deck-of-cards 英文原文In a deck of cards, each card has an integer written on it. Return true if and only if you can choose X >= 2 such that it is possible to split the entire deck into 1 or more gr…

原文链接: https://leetcode-cn.com/problems/partition-array-into-disjoint-intervals 英文原文Given an integer array nums, partition it into two (contiguous) subarrays left and right so that: Every element in left is less than or equal to every element in right…

原文链接: https://leetcode-cn.com/problems/reverse-only-letters 英文原文Given a string s, reverse the string according to the following rules: All the characters that are not English letters remain in the same position. All the English letters (lowercase or …

原文链接: https://leetcode-cn.com/problems/word-subsets 英文原文You are given two string arrays words1 and words2. A string b is a subset of string a if every letter in b occurs in a including multiplicity. For example, "wrr" is a subset of "warrior" but is …

原文链接: https://leetcode-cn.com/problems/complete-binary-tree-inserter 英文原文A complete binary tree is a binary tree in which every level, except possibly the last, is completely filled, and all nodes are as far left as possible. Design an algorithm to i…

原文链接: https://leetcode-cn.com/problems/number-of-music-playlists 英文原文Your music player contains n different songs. You want to listen to goal songs (not necessarily different) during your trip. To avoid boredom, you will create a playlist so that: Ev…

原文链接: https://leetcode-cn.com/problems/minimum-add-to-make-parentheses-valid 英文原文A parentheses string is valid if and only if: It is the empty string, It can be written as AB (A concatenated with B), where A and B are valid strings, or It can be writ…

原文链接: https://leetcode-cn.com/problems/sort-array-by-parity-ii 英文原文Given an array of integers nums, half of the integers in nums are odd, and the other half are even. Sort the array so that whenever nums[i] is odd, i is odd, and whenever nums[i] is e…