LeetCode-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.

　　

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