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.

本题要求求出ugly number，不是很难，但是要注意考虑边界条件，比如1，0两种情况，代码如下：

public class Solution {
    public boolean isUgly(int num) {
        int[] factor = new int[]{2,3,5};
        if(num==0) return false;
        for(int i=0;i<factor.length;i++){
            while(num%factor[i]==0){
                num/=factor[i];
            }
        }
        return num==1;
    }
}