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