[LeetCode]--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.

Credits:
Special thanks to @jianchao.li.fighter for adding this problem and creating all test cases.

public boolean isUgly(int num) {
        if (num <= 0)
            return false;
        if (num == 1)
            return true;

        while (num >= 2 && num % 2 == 0)
            num /= 2;
        while (num >= 3 && num % 3 == 0)
            num /= 3;
        while (num >= 5 && num % 5 == 0)
            num /= 5;

        return num == 1;
    }