#include<stdio.h>

main()
{
int n,i,a[20],key;
printf("Enter n:");
scanf("%d",&n);

printf("Enter elements into array:\n");
for(i=0; i<n; i++)
{ scanf("%d",&a[i]);
}
printf("Enter element to be searched\n");
scanf("%d",&key);

int start=0,end=n-1,mid;

while(start<=end)
{
mid=(start+end)/2;
if(a[mid]==key)
{
printf("%d found at %d",key,mid+1);
break;
}
else if(key<a[mid])
{
end=mid-1;
}
else
{
start=mid+1;
}
}

if(start>end)
{
printf("Element not found!!");
}
}

     
           
Note: Need to be arranged in compiler after copied
   

 OutPut:

Enter n:5 Enter elements into array: 2 4 6 8 9 Enter element to be searched 4 4 found at 2