#include
using namespace std;
int binary_search(int a[],int n)
{
int s=0;
int e=n-1;
int mid;
while(s<=e)
{
mid=(s+e)/2;
if(a[mid]==key)
{
return mid;
}
else if(a[mid]>key)
{
e=mid-1;
}
else(a[mid]<key)
{
s=mid+1;
}
}
return -1;
}
int main(){
int n,key;
cout<<“enter n=”;
cin>>n;
for(i=0;i<n;i++)
{
cin<<a[i]<<",";
}
cout<<“element to be searched=”;
cin>>key;
cout<<binary_search(a,n,key)<<endl;
return 0;
}