Design a Phone Directory which supports the following operations:   get: Provide a number which is…

  Median is the middle value in an ordered integer list. If the size of the list is even, there is no mid…

  Given a non-empty 2D array grid of 0’s and 1’s, an island is a group of…

题目描述 Given a 2d grid map of ‘1’s (land) and ‘0’s (water), count the number of islands. An island is surrounded…

最新更新请见：https://yanjia.me/zh/2019/01/… There are n cities connected by m flights. Each fight starts from …

Given a collection of numbers, return all possible permutations. For example,[1,2,3] have the following p…

一、题目原型： 给定一个整数数组，判断是否存在重复元素。 如果任何值在数组中出现至少两次，函数返回 true。如果数组中每个元素都不相同，则返回 false。 二、题目意思剖析： 示例 1: 输入: [1,2,3,1] …

Problem More LeetCode Discussions You want to build a house on an empty land which reaches all buildings in th…

题意：给你一个数，判断是不是回文数。回文数：一个数从左读和从右读一样（注：最好不要将int转换为string）。 解题思路： 先判断该数是不是负数，如果是负数返回false； 思路一、可以使用一个map将位置与该位置的数…

My code: public class Solution { public boolean isPowerOfThree(int n) { return n > 0 && Math.pow(3,…

题目 Given a binary array, find the maximum number of consecutive 1s in this array. Example 1: Input: [1,1,0,1,1…

  You are given several logs that each log contains a unique id and timestamp. Timestamp is a string that…