#include <set>

struct Room
{
    Room* north;
    Room* east;
    Room* south;
    Room* west;
};

class Maze
{
public:
    Maze(Room* entrance) : entrance{entrance} {}

    /* Everything but the destructor is given
       (except any includes needed for the destructor) */

    ~Maze()
    {
        std::set<Room*> visited { };
        remove_rooms(entrance, visited);
    }
    
    Maze(Maze const& other) = delete;
    Maze(Maze && other) = delete;    
    Maze operator=(Maze const& other) = delete;
    Maze operator=(Maze && other) = delete;
    
private:

    void remove_rooms(Room* room, std::set<Room*>& visited)
    {
        if (room == nullptr)
            return;
        
        if (visited.count(room) > 0)
            return;

        visited.insert(room);
        remove_rooms(room->north, visited);
        remove_rooms(room->east,  visited);
        remove_rooms(room->south, visited);
        remove_rooms(room->west,  visited);
        delete room;
    }
    
    Room* entrance;

};

Room* setup_rooms()
{
    Room* r1{ new Room{} };
    Room* r2{ new Room{} };
    Room* r3{ new Room{} };
    Room* r4{ new Room{} };
    Room* r5{ new Room{} };
    Room* r6{ new Room{} };

    r1->east=r2;  r1->south=r4;
    r2->east=r3;  r2->south=r5; r2->west=r1;
    r3->south=r6; r3->west=r2;
    r4->north=r1; r4->east=r5;
    r5->north=r2; r5->west=r4;
    r6->north=r3;
    return r1;
}

int main()
{
    Maze maze{setup_rooms()};
}