C PROGRAMMING -- BINARY SEARCH

#include<conio.h>
#include<stdio.h>
void main()
{ int i,last,first,middle,n,search,a[100];
printf("enter the no of elements=\n");
scanf("%d",&n);
printf("enter %d integers\n",n);
for(i=0;i<n;i++)
scanf("%d",&a[i]);
printf("enter the element to search-\n");
scanf("%d",&search);
first=0;
last=n-1;
middle=(first+last)/2;
while(first<=last)
{
if(a[middle]<search)
first=middle+1;
else if(a[middle]==search)
{
printf("%d found at %d.\n",search,middle+1);
break;
}
else last=middle-1;
middle=(first+last)/2;
}
if(first>last)
printf("not found %d sorry.\n",search);
getch();
}