mz07-2

#include <iostream>
#include <vector>
#include <iterator>
#include <algorithm>

void
process(std::vector<int> &a)
{
    auto insert = a.begin();
    int number = 0;
    for (auto it = a.begin(); it != a.end(); ++it, ++number) {
        if (number & 1) {
            *(insert++) = *it;
        }
    }
    a.resize(a.size() / 2);
    std::copy(a.rbegin(), a.rend(),   std::ostream_iterator<int>(std::cout, " "));
}