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

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

Simplify UglyNum_001.java