Implement Binary Search using recursion.

binarySearchUsingRecursion.cpp

bool binary_search(vector<int> sorted_nums, int low, int high, int K) {
    if (low > high) {
        return false;
    }

    int mid = (low+high)/2;
    if (sorted_nums[mid] == K) {
        return true;
    }

    bool is_found = false;
    if (sorted_nums[mid] < K) {
        is_found = binary_search(sorted_nums, mid + 1, high, K);
    } else {
        is_found = binary_search(sorted_nums, low, mid - 1, K);
    }
    return is_found;
}