// C program to implement recursive Binary Search
#include <stdio.h>// A recursive binary search function. It returns
// location of x in given array arr[l..r] is present,
// otherwise -1
int binarySearch(int arr[], int l, int r, int x)
{
if (r >= l) {
int mid = l + (r - l) / 2;// If the element is present at the middle
// itself
if (arr[mid] == x)
return mid;// If element is smaller than mid, then
// it can only be present in left subarray
if (arr[mid] > x)
return binarySearch(arr, l, mid - 1, x);// Else the element can only be present
// in right subarray
return binarySearch(arr, mid + 1, r, x);
}// We reach here when element is not
// present in array
return -1;
}int main(void)
{
int arr[] = { 2, 3, 4, 10, 40 };
int n = sizeof(arr) / sizeof(arr[0]);
int x = 10;
int result = binarySearch(arr, 0, n - 1, x);
(result == -1) ? printf("Element is not present in array")
: printf("Element is present at index %d",
result);
return 0;
}
https://www.geeksforgeeks.org/binary-search/
