Program in C++ to demonstrate Binary Search.

#include <iostream.h>
#include<conio.h>
int BinarySearch(int [], int, int );
void main()
{
    clrscr();
    int n,i,arr[50],item,location;
    cout<<"\nEnter Numbers of elements you have :\n";
    cin>>n;
    cout<<"\nEnter "<<n<<" Elements :\n";
    for(i=0;i<n;i++)cin>>arr[i];
    cout << "Enter the item you are searching for: ";
    cin >> item;
    location = BinarySearch(arr,n,item);
    if (location > -1)
    cout << "The item was found at index location "<< location+1;
    else
    cout << "The item was not found in the list\n";
    getch();
}
int BinarySearch(int list[], int size, int key)
{
    int left, right, midpt;
    left = 0;
    right = size-1;
    while (left <= right)
        {
            midpt = (left + right) / 2;
            if (key == list[midpt])
            {
                return midpt;
            }
            else if (key > list[midpt])
                left = midpt + 1;
            else
                right = midpt - 1;
        }
    return -1;
}