/**
 * @param {number} n
 * @return {boolean}
 */
var isPowerOfThree = function(n) {
    if (n ===1) {
        return true;
    }
    while(true) {
        n = n/3;
        if (n === 1) {
            return true;
        } else if(n < 1) {
            return false;
        }
    }
};

console.info(isPowerOfThree(0));