binary.1

#include<bits/stdc++.h>
using namespace std;
int binarysearch(int arr[],int size,int key)
{
    int start = 0,end = size -1;
   int mid =  start + (end - start)/2;
   while(start<=end)
   {
       if(arr[mid]==key)
       {
           return mid;
       }
       else if(arr[mid]>key)
       {
          end = mid -1;
       }
       else
       start = mid+1;
       
        mid  = start + (end - start)/2;
   }

   return -1;

}
int main()
{
    int arr[10000],n,key;
    cout<<"enter the size of the array: ";
    cin>>n;
    cout<<"enter the key : ";
    cin>>key;
    int index;
    for(index=0;index<n;index=index+1)
    {
        cout<<"arr["<<index<<"] : ";
        cin>>arr[index];
    }
cout<<binarysearch(arr,n,key);
  
    
    
    return 0;
}