struct Key // koordynaty hexa
{
    int x, y, z;
    Key(int x, int y, int z) : x(x), y(y), z(z) {}

    bool operator==(const Key &other) const
    {
        return (x == other.x && y == other.y && z == other.z);
    }
};

struct KeyHasher
{
    const int c = 1000; // wartosc wieksza niz bok mapy i c^3 < max unsigned long size
    std::size_t operator()(const Key& k) const
    {
        return static_cast<std::size_t>(x + (y*c) + (z*c*c));
    }
};