【LeetCode】(263)Ugly Number(Easy)

题目

Ugly Number

 Total Accepted: 4084 Total Submissions: 12843My Submissions

Question Solution 

Write a program to check whether a given number is an ugly number.

Ugly numbers are positive numbers whose prime factors only include 2, 3, 5. For example, 6, 8 are ugly while 14 is not ugly since it includes another prime factor 7.

Note that 1 is typically treated as an ugly number.

Credits:
Special thanks to @jianchao.li.fighter for adding this problem and creating all test cases.

解析

很简单，能被2，3，5整除的时候就把数字除以他们，遇到除不尽的时候就说明不是了。

需要特殊考虑0 和 1.

代码如下

class Solution {public:    bool isUgly(int num) {        if (num == 1) return true;        else if(num == 0)            return false; while (num != 1) { if (num%2 == 0) { num = num/2; } else if (num%3 == 0) { num = num/3; } else if (num%5 == 0) { num = num/5; } else return false; } return true;    }};