Write a program to perform binary search
using recursion.
 #include <stdio.h>
#include <conio.h>
 int main( )
 {
 int arr[10] = { 1, 2, 3, 9, 11, 13, 17, 25,
57, 90 } ;
 int mid, lower = 0 , upper = 9, num, flag = 1
;
clrscr();
 printf ( "Enter number to search: "
) ;
 scanf ( "%d", &num ) ;
 for ( mid = ( lower + upper ) / 2 ; lower
<= upper ;
 mid = ( lower + upper ) / 2 )
 {
 if ( arr[mid] == num )
 {
 printf ( "The number is at position %d in
the array.", mid ) ;
 flag = 0 ;
 break ;
 }
 if ( arr[mid] > num )
 upper = mid - 1 ;
 else
 lower = mid + 1 ;
 }
 if ( flag )
 printf ( "Element is not present in the
array." ) ;
 }
Output
