leetcode-java-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.

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