Given an integer, write a function to determine if it is a power of three.

public class Solution {
    public boolean isPowerOfThree(int n) {
        if (n <= 0) return false;
        while (n % 3 == 0) {
            n /= 3;
        }
        return n == 1;
    }

    public boolean isPowerOfThree(int n) {
        return (Math.log10(n) / Math.log10(3)) % 1 == 0;
    }
}

class Solution(object):
    def isPowerOfThree(self, n):
        """
        :type n: int
        :rtype: bool
        """

        #3^20 is bigger than int
        return n > 0 and 3 ** 19 % n == 0