263. 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：modulo 2,3,5检查最后是不是全被整除了。

论coding style之美。。。。

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