xinyu04

摘要： Given an m x n integer matrix matrix, if an element is $0$, set its entire row and column to $0$'s. You must do it in place. Solution 做法并不难，但如果考虑常数空间复 阅读全文

摘要： Design a stack that supports push, pop, top, and retrieving the minimum element in constant time. Implement the MinStack class: MinStack() initializes 阅读全文

摘要： You are given an m x n binary matrix grid. An island is a group of 1's (representing land) connected 4-directionally (horizontal or vertical.) You may 阅读全文

摘要： An image is represented by an m x n integer grid image where image[i][j] represents the pixel value of the image. You are also given three integers sr 阅读全文

摘要： There is a long and thin painting that can be represented by a number line. You are given a 0-indexed 2D integer array paint of length n, where paint[ 阅读全文

摘要： Given two strings s1 and s2, return true if s2 contains a permutation of s1, or false otherwise. In other words, return true if one of s1's permutatio 阅读全文

摘要： Given a string s, find the length of the longest substring without repeating characters. Solution 求最长的不重复子串。我们利用左右两个指针来模拟端点，然后用 $set$ 来记录出现过的字符。当出现重复的 阅读全文

摘要： You are given an integer array prices where prices[i] is the price of a given stock on the $i$th day. On each day, you may decide to buy and/or sell t 阅读全文

摘要： You are given an array prices where prices[i] is the price of a given stock on the $i$th day. You want to maximize your profit by choosing a single da 阅读全文

摘要： Given an array of intervals where intervals[i] = [starti, endi], merge all overlapping intervals, and return an array of the non-overlapping intervals 阅读全文