Problema: http://www.pbinfo.ro/?pagina=probleme&id=488

#include <iostream>
#include <algorithm>

using namespace std;

int n, v, k[10000];

int main()
{
    cin >> n;
    for (int i=1; i<=n; i++)
    {
        cin >> k[i];
    }
    for (int i=1; i<=n; i++)
    {
        if (i % 2 == 0)
        {
            cout << k[i] << " " ;
        }
    }
    cout << endl;
    for (int i=n; i>0; i--)
    {
        if (i % 2 == 1)
        {
            cout << k[i] << " " ;
        }
    }
    return 0;
}