Binary Search - Find the number

#include <iostream>
using namespace std;

int binarysearch(const int[], int, int);
const int size = 10;

int main()
{
    int idin[size] = {12, 32, 32, 234, 12, 32, 14, 34, 12, 534};
    int result, empID;

    cout << "Enter an ID number to get where it is stored: ";
    cin >> empID;

    result = binarysearch(idin, size, empID);

    if (result == -1)
    {
        cout << "The ID number does not exist in the array.\n";
    }
    else
    {
        cout << "The ID is found at element " << result + 1 << endl;
    }

    return 0;
}

int binarysearch(const int array[], int size, int value)
{
    int first = 0, last = size - 1, middle, position = -1;
    bool found = false;

    while (!found && first <= last)
    {
        middle = (first + last) / 2;
        if (array[middle] == value)
        {
            found = true;
            position = middle;
        }
        else if (array[middle] > value)
        {
            last = middle - 1;
        }
        else
        {
            first = middle + 1;
        }
    }

    return position;
}