bin_src rec

#include <iostream>
using namespace std;

int rec_binarySearch(int arr[], int st, int dr, int x)
{
    if (st <= dr)
    {
        int m = (st + dr)/2;
        if (x == arr[m])
            return m;
        if (x < arr[m])
            return rec_binarySearch(arr, st, m - 1, x);
        return rec_binarySearch(arr, m + 1, dr, x);
    }
    return -1;
}

int main(void)
{
    int arr[] = {2, 3, 4, 10, 40};
    int n = sizeof(arr)/ sizeof(int);
    int x = 10;
    int res = rec_binarySearch(arr, 0, n - 1, x);
    if (res != -1)
        cout<<"Index: " << res;
    else
        cout<<"Element inexistent!";
    return 0;
}