(leetcode)Ugly Number

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.

思路1：将需要num分别对2,3,5取余，最后判断最后的数是否为1，如果是就为丑数 

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