#include <iostream>
#include <memory>

struct Casa {
    int id;
    std::shared_ptr<Casa> esquerda;
    std::weak_ptr<Casa> direita;
};

int main(int, char *[])
{
    auto c1 = std::make_shared<Casa>();
    c1->id = 1;
    {
        auto c2 = std::make_shared<Casa>();
        c2->id = 2;

        std::shared_ptr<Casa> outra;
        outra = c1;

        c2->esquerda = c1;
        c1->direita = c2;
        auto c1dirshared = c1->direita.lock();
        std::cout << c1->id << " ";
        if (c1dirshared) {
            std:: cout << c1dirshared->id << std::endl;
        }
        else {
            std::cout << "nulo" << std::endl;
        }
        std::cout << c2->id << " "
                  << c2->esquerda->id << std::endl;
    }
    auto c1dirshared = c1->direita.lock();
    std::cout << c1->id << " ";
    if (c1dirshared) {
        std:: cout << c1dirshared->id << std::endl;
    }
    else {
        std::cout << "nulo" << std::endl;
    }

    return 0;
}