7. Write a C Program to search an element using recursive binary search technique.
   
#include < stdio.h>
#include < conio.h>

int binarySearch(int arr[], int left, int right, int key) {
   
    if (right >= left) {
        int mid = left + (right - left) / 2;
        if (arr[mid] == key)
            return mid;

        if (arr[mid] > key)  {
            return binarySearch(arr, left, mid - 1, key);
        }
        return binarySearch(arr, mid + 1, right, key);
    }
return -1;
}

void  main(void) {
    int arr[] = {2, 5, 8, 12, 16, 23, 38, 56, 72, 91};
    int size = sizeof(arr) / sizeof(arr[0]);
  
    int key = 23;
  
    int index = binarySearch(arr, 0, size - 1, key);
    if (index == -1) {
        printf("Element is not present in array");
    }
    else {
        printf("Element is present at index %d", index);
    }

   getch();
}