摘要： Given a 32-bit signed integer, reverse digits of an integer. Example 1: Example 2: Example 3: 题意： 给定一个10进制整数，翻转它。 Solution1: directly do the simulatio 阅读全文

摘要： There are two sorted arrays nums1 and nums2 of size m and n respectively. Find the median of the two sorted arrays. The overall run time complexity sh 阅读全文

摘要： You are given two non-empty linked lists representing two non-negative integers. The digits are stored in reverse order and each of their nodes contai 阅读全文

摘要： [leetcode]1. Two Sum两数之和 Two Pointers, HashMap Easy [leetcode]2. Add Two Numbers两数相加 Math, LinkedList Medium [leetcode]3. Longest Substring Without Re 阅读全文

摘要： There are a total of n courses you have to take, labeled from 0 to n-1. Some courses may have prerequisites, for example to take course 0 you have to 阅读全文

摘要： 定义： Topological Sorting is a method of arranging the vertices in a directed acyclic graph (DAG有向无环图) as a sequence, such that for every directed edge( 阅读全文

摘要： A robot is located at the top-left corner of a m x n grid (marked 'Start' in the diagram below). The robot can only move either down or right at any p 阅读全文

摘要： Given a string, find the first non-repeating character in it and return it's index. If it doesn't exist, return -1. Examples: Note: You may assume the 阅读全文

摘要： Say you have an array for which the ith element is the price of a given stock on day i. Design an algorithm to find the maximum profit. You may comple 阅读全文

摘要： Say you have an array for which the ith element is the price of a given stock on day i. Design an algorithm to find the maximum profit. You may comple 阅读全文