void diamond(int nFloors)
{
    for (int i = 0; i < nFloors; ++i) {
        for (int j = 0; j < nFloors; ++j) {
            abs(nFloors/2-i)+abs(nFloors/2-j) <=nFloors/2 ? std::cout << "*" : std::cout << " ";
        }
        std::cout << "\n";
    }
}