leetcode263 丑数

//Time:O(m+n+l) m为多少个2，n为多少个3,l为多少个5，Space:O(1)
class Solution 
{
public:
    bool isUgly(int num) 
    {
        if(num<=0) return false;
        while(num%2==0) num/=2;
        while(num%3==0) num/=3;
        while(num%5==0) num/=5;

        return num==1;
    }
};