#include <iostream>

const int ArSize = 8;
int sum_arr(const int *begin, const int *end);

int main()
{
    using namespace std;
    int cookies[ArSize] = {1, 2, 4, 8, 16, 32, 64, 128};

    int sum = sum_arr(cookies, cookies + ArSize);
    cout << "Total cookies eaten: " << sum << endl;
    sum = sum_arr(cookies, cookies + 3);
    cout << "First three eaters ate " << sum << " cookies.\n";
    sum = sum_arr(cookies + 4, cookies + 8);
    cout << "Last four eaters ate " << sum << " cookies.\n";
}

int sum_arr(const int *begin, const int *end)
{
    const int *pt;
    int total = 0;

    for (pt = begin; pt != end; pt++)
    {
        total = total + *pt;
    }
    return total;
}