leetcode 263. Ugly Number

Seawolf

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.

Example 1:

Input: 6
Output: true
Explanation: 6 = 2 × 3
Example 2:

Input: 8
Output: true
Explanation: 8 = 2 × 2 × 2
Example 3:

Input: 14
Output: false 
Explanation: 14 is not ugly since it includes another prime factor 7.
Note:

1 is typically treated as an ugly number.
Input is within the 32-bit signed integer range: [−231,  231 − 1].

class Solution {
    public boolean isUgly(int num) {
        if(num == 1) return true;
        if(num == 0) return false;
        int a = 2;
        while(a != 0 && num % a == 0){
            a = a * 2;
        }
        a = a /2 ;
        if(a != 0)
            num = num / a;
        a =3;
        while(a != 0 && num % a == 0){
            a = a * 3;
        }
        
        a = a /3;
        // System.out.println(b);
        if(a != 0)
            num = num / a;
        a = 5;
        while(a != 0 && num % a == 0){
            a = a * 5;
        }
        a = a /5;
        if(a != 0)
            num = num / a;
        if(num == 1) return true;
        else
            return false;
    }
}