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.

 1 public class Solution {
 2     public boolean isUgly(int num) {
 3         if (num <= 0) return false;
 4         while (num != 1) {
 5             if (num % 2 == 0) num /= 2;
 6             else if (num % 3 == 0) num /= 3;
 7             else if (num % 5 == 0) num /= 5;
 8             else return false;
 9         }
10         return true;
11     }
12 }