原文链接: https://leetcode-cn.com/problems/remove-palindromic-subsequences 英文原文You are given a string s consisting only of letters 'a' and 'b'. In a single step you can remove one palindromic subsequence from s. Return the minimum number of steps to make…

原文链接: https://leetcode-cn.com/problems/filter-restaurants-by-vegan-friendly-price-and-distance 英文原文Given the array restaurants where restaurants[i] = [idi, ratingi, veganFriendlyi, pricei, distancei]. You have to filter the restaurants using three fi…

原文链接: https://leetcode-cn.com/problems/find-the-city-with-the-smallest-number-of-neighbors-at-a-threshold-distance 英文原文There are n cities numbered from 0 to n-1. Given the array edges where edges[i] = [fromi, toi, weighti] represents a bidirectional …

原文链接: https://leetcode-cn.com/problems/minimum-difficulty-of-a-job-schedule 英文原文You want to schedule a list of jobs in d days. Jobs are dependent (i.e To work on the i-th job, you have to finish all the jobs j where 0 <= j < i). You have to finish at…

原文链接: https://leetcode-cn.com/problems/sort-integers-by-the-number-of-1-bits 英文原文Given an integer array arr. You have to sort the integers in the array in ascending order by the number of 1's in their binary representation and in case of two or more …

原文链接: https://leetcode-cn.com/problems/apply-discount-every-n-orders 英文原文There is a supermarket that is frequented by many customers. The products sold at the supermarket are represented as two parallel integer arrays products and prices, where the i…

原文链接: https://leetcode-cn.com/problems/number-of-substrings-containing-all-three-characters 英文原文Given a string s consisting only of characters a, b and c. Return the number of substrings containing at least one occurrence of all these characters a, b…

原文链接: https://leetcode-cn.com/problems/the-k-weakest-rows-in-a-matrix 英文原文You are given an m x n binary matrix mat of 1's (representing soldiers) and 0's (representing civilians). The soldiers are positioned in front of the civilians. That is, all th…

原文链接: https://leetcode-cn.com/problems/reduce-array-size-to-the-half 英文原文You are given an integer array arr. You can choose a set of integers and remove all the occurrences of these integers in the array. Return the minimum size of the set so that at…

原文链接: https://leetcode-cn.com/problems/maximum-product-of-splitted-binary-tree 英文原文Given the root of a binary tree, split the binary tree into two subtrees by removing one edge such that the product of the sums of the subtrees is maximized. Return th…

原文链接: https://leetcode-cn.com/problems/jump-game-v 英文原文Given an array of integers arr and an integer d. In one step you can jump from index i to index: i + x where: i + x < arr.length and 0 < x <= d. i - x where: i - x >= 0 and 0 < x <= d. In additio…

原文链接: https://leetcode-cn.com/problems/check-if-n-and-its-double-exist 英文原文Given an array arr of integers, check if there exists two integers N and M such that N is the double of M ( i.e. N = 2 * M). More formally check if there exists two indices i …

原文链接: https://leetcode-cn.com/problems/minimum-number-of-steps-to-make-two-strings-anagram 英文原文Given two equal-size strings s and t. In one step you can choose any character of t and replace it with another character. Return the minimum number of ste…

原文链接: https://leetcode-cn.com/problems/tweet-counts-per-frequency 英文原文A social media company is trying to monitor activity on their site by analyzing the number of tweets that occur in select periods of time. These periods can be partitioned into sma…

原文链接: https://leetcode-cn.com/problems/maximum-students-taking-exam 英文原文Given a m * n matrix seats that represent seats distributions in a classroom. If a seat is broken, it is denoted by '#' character otherwise it is denoted by a '.' character. Stud…

原文链接: https://leetcode-cn.com/problems/find-the-longest-substring-containing-vowels-in-even-counts 英文原文Given the string s, return the size of the longest substring containing each vowel an even number of times. That is, 'a', 'e', 'i', 'o', and 'u' mu…

原文链接: https://leetcode-cn.com/problems/longest-zigzag-path-in-a-binary-tree 英文原文You are given the root of a binary tree. A ZigZag path for a binary tree is defined as follow: Choose any node in the binary tree and a direction (right or left). If the …

原文链接: https://leetcode-cn.com/problems/maximum-sum-bst-in-binary-tree 英文原文Given a binary tree root, return the maximum sum of all keys of any sub-tree which is also a Binary Search Tree (BST). Assume a BST is defined as follows: The left subtree of a…

原文链接: https://leetcode-cn.com/problems/count-negative-numbers-in-a-sorted-matrix 英文原文Given a m x n matrix grid which is sorted in non-increasing order both row-wise and column-wise, return the number of negative numbers in grid. Example 1: Input: gri…

原文链接: https://leetcode-cn.com/problems/product-of-the-last-k-numbers 英文原文Design an algorithm that accepts a stream of integers and retrieves the product of the last k integers of the stream. Implement the ProductOfNumbers class: ProductOfNumbers() In…

原文链接: https://leetcode-cn.com/problems/maximum-number-of-events-that-can-be-attended 英文原文Given an array of events where events[i] = [startDayi, endDayi]. Every event i starts at startDayi and ends at endDayi. You can attend an event i at any day d wh…

原文链接: https://leetcode-cn.com/problems/construct-target-array-with-multiple-sums 英文原文You are given an array target of n integers. From a starting array arr consisting of n 1's, you may perform the following procedure : let x be the sum of all element…

原文链接: https://leetcode-cn.com/problems/how-many-numbers-are-smaller-than-the-current-number 英文原文Given the array nums, for each nums[i] find out how many numbers in the array are smaller than it. That is, for each nums[i] you have to count the number …

原文链接: https://leetcode-cn.com/problems/minimum-cost-to-make-at-least-one-valid-path-in-a-grid 英文原文Given a m x n grid. Each cell of the grid has a sign pointing to the next cell you should visit if you are currently in this cell. The sign of grid[i][j…

原文链接: https://leetcode-cn.com/problems/linked-list-in-binary-tree 英文原文Given a binary tree root and a linked list with head as the first node. Return True if all the elements in the linked list starting from the head correspond to some downward path c…

原文链接: https://leetcode-cn.com/problems/find-the-distance-value-between-two-arrays 英文原文Given two integer arrays arr1 and arr2, and the integer d, return the distance value between the two arrays. The distance value is defined as the number of elements…

原文链接: https://leetcode-cn.com/problems/cinema-seat-allocation 英文原文 A cinema has n rows of seats, numbered from 1 to n and there are ten seats in each row, labelled from 1 to 10 as shown in the figure above. Given the array reservedSeats containing th…

原文链接: https://leetcode-cn.com/problems/sort-integers-by-the-power-value 英文原文The power of an integer x is defined as the number of steps needed to transform x into 1 using the following steps: if x is even then x = x / 2 if x is odd then x = 3 * x + 1…

原文链接: https://leetcode-cn.com/problems/pizza-with-3n-slices 英文原文There is a pizza with 3n slices of varying size, you and your friends will take slices of pizza as follows: You will pick any pizza slice. Your friend Alice will pick next slice in anti …

原文链接: https://leetcode-cn.com/problems/generate-a-string-with-characters-that-have-odd-counts 英文原文Given an integer n, return a string with n characters such that each character in such string occurs an odd number of times. The returned string must co…