Code Golf Binary Search

binary_search.c

#define i int
#define x return
i b(i*a,i k,i l,i r){i m=(l+r)/2;x a[m]==k?m:l>=r?-1:k<a[m]?b(a,k,l,m-1):b(a,k,m+1,r);}

Here is the program to test the function.

#include<stdio.h>
int main(){
  int arr[] = {4, 6, 7, 8, 9, 12};
  int key = 12;
  int i = b(arr, key, 0, sizeof(arr) / sizeof(arr[0]));
  if(i==-1) printf("Key doesn't exist");
  else printf("Key exists at index %d", i);
  return 0;
}

#include<stdio.h>
int main(){
int arr[] = {4, 6, 7, 8, 9, 12},key = 12, i = b(arr, key, 0, sizeof(arr) / sizeof(arr[0]));
(i==-1)? printf("Key doesn't exist"):printf("Key exists at index %d", i);
return 0;
}

#include<stdio.h>
int main(){
int arr[] = {4, 6, 7, 8, 9, 12},key = 12, i = b(arr, key, 0, sizeof(arr) / sizeof(arr[0]));
(i==-1)? printf("Key doesn't exist"):printf("Key exists at index %d", i);
return 0;
}

you need to optimize the function, not the driving code 😆 Try to shorten the original binary_search.c file.