题意: 给出一个整数n,判断其是否为幸运数. 规则是,将n按十进制逐位拆出来后,每个位各自进行取平方,再将这些平方数求和作为新的数字n.若最后n=1,就是幸运数. 思路: 计算例子:n=47,接着n=4*4+7*7=65,接着n=6*6+5*5=61,接着.... 注意有可能陷入无限循环,就是迭代的过程产生了一个环路,即n又重复出现了. class Solution { public: bool isHappy(int n) { unordered_set<int> sett; ) { if(…

Validate if a given string is numeric. Some examples:"0" => true" 0.1 " => true"abc" => false"1 a" => false"2e10" => true Note: It is intended for the problem statement to be ambiguous. You…

We define the Perfect Number is a positive integer that is equal to the sum of all its positive divisors except itself. Now, given an integer n, write a function that returns true when it is a perfect number and false when it is not. Example: Input:…

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…

---Number类型的细节,其包含的基本数字类型 ---Number基本数字类型之间的数值转换 ---Number上面的数学函数,有些可以直接调用,有些需要导入库 参见http://www.runoob.com/python/python-numbers.html 扩充下面的笔记…

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…