leetcode 263. Ugly Number

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