Return whether or not 'n' is a power of three.

IsPowerOfThree.kt

/*
Given an integer n, return true if it is a power of three. Otherwise, return false.
An integer n is a power of three, if there exists an integer x such that n == 3x.

Example 1:
Input: n = 27
Output: true

Example 2:
Input: n = 0
Output: false
* */

fun isPowerOfThree(n: Int): Boolean {
    return if (n == 1 || n == 3) {
        true
    } else if (n == 0 || n % 3 != 0) {
        false
    } else {
        isPowerOfThree(n / 3)
    }
}