To Search an element using binary search.

 Program:
#include<stdio.h>
#include<conio.h>
int Binarysearch(int[],int,int);
void main()
{
int x[20],i,n,p,key;
clrscr();
printf("\n Enter the no of element:");
scanf("%d",&n);
printf("\n Enter %d elements in assending order:",n);
for(i=0;i<n;i++)
scanf("%d",&x[i]);
printf("\n Enter the element to be search:");
scanf("%d",&key);
p=Binarysearch(x,n,key);
if(p==-1)
printf("\n The searchis unsuccessful:\n");
else
printf("\n%d is found at location %d",key,p);
getch();
}
int Binarysearch(int a[],int n ,int k)
{
int lo,hi,mid;
lo=0;
hi=n-1;
while(lo<=hi)
{
mid=(lo+hi)/2;
if(k==a[mid])
return(mid);
if(k<a[mid])
hi=mid-1;
else
lo=mid+1;
}
return(-1);
}