isPowerTwo.cpp

bool isPowerTwo(int number) {
    bool hasOne = false;
    unsigned int current = number;
    while (true) {
        /* If the number was 0, then hasOne is false. Otherwise,
         * hasOne is true, but since we are here, the number had only
         * one bit as 1.  Thus the number is a power of two.
         */
        if (current == 0) return hasOne;
        if ((current & 1) == 1) {
            /* If a number has more than one bit as 1, then it is not
             * a power of two.
             */
            if (hasOne) return false;
            hasOne = true;
        }
        // Remove a bit.
        current = current >> 1;
    }
}

vector <int> isPowerOf2(vector <int> nums) {
    vector <int> answers = {};
    for (int i = 0; i < nums.size(); i++) {
        answers.push_back(isPowerTwo(nums[i]));
    }
    return answers;
}