判断integer是否为回文串(负数全部不为回文串) 思路很直接,提取出integer中的每一位,一头一尾进行比较是否相同. 一次AC , 直接上代码: public boolean isPalindrome(int x) { if(x < 0) return false; else if(x >= 0 && x <= 9) return true; else{ int[] num = new int[20]; int i = 0 ; while(x > 0){ n…

版权声明: 本文为博主Bravo Yeung(知乎UserName同名)的原创文章,欲转载请先私信获博主允许,转载时请附上网址 http://blog.csdn.net/lzuacm. C#版 - Leetcode 191. Number of 1 Bits题解 191. 位1的个数 在线提交: https://leetcode-cn.com/problems/number-of-1-bits/description/ 题目描述 编写一个函数,输入是一个无符号整数,返回其二进制表达式中数字位数为…

Given a 2d grid map of '1's (land) and '0's (water), count the number of islands. An island is surrounded by water and is formed by connecting adjacent lands horizontally or vertically. You may assume all four edges of the grid are all surrounded by…

Given a non-empty 2D array grid of 0's and 1's, an island is a group of 1's (representing land) connected 4-directionally (horizontal or vertical.) You may assume all four edges of the grid are surrounded by water. Count the number of distinct island…

Given a non-empty 2D array grid of 0's and 1's, an island is a group of 1's (representing land) connected 4-directionally (horizontal or vertical.) You may assume all four edges of the grid are surrounded by water. Count the number of distinct island…

Given a non-empty 2D array grid of 0's and 1's, an island is a group of 1's (representing land) connected 4-directionally (horizontal or vertical.) You may assume all four edges of the grid are surrounded by water. Count the number of distinct island…

Leetcode ugly number set (3 now) new ugly number is generated by multiplying a prime with previous generated ugly numbe Is ugly number or not class Solution { public boolean isUgly(int num) { if(num==0) return false; //how to generate the number whil…

Given a 2d grid map of '1's (land) and '0's (water), count the number of islands. An island is surrounded by water and is formed by connecting adjacent lands horizontally or vertically. You may assume all four edges of the grid are all surrounded by…

A 2d grid map of m rows and n columns is initially filled with water. We may perform an addLand operation which turns the water at position (row, col) into a land. Given a list of positions to operate, count the number of islands after each addLand o…

Given n nodes labeled from 0 to n - 1 and a list of undirected edges (each edge is a pair of nodes), write a function to find the number of connected components in an undirected graph. Example 1: 0        3 |          | 1 --- 2    4 Given n = 5 and e…