struct cluster {
    shared_ptr<cluster> left,right;
    weak_ptr<cluster> father;
    cluster(){}
    cluster(cluster& left,cluster& right) {
        right.father = left.father = shared_ptr<cluster>(this);
        this->left = shared_ptr<cluster>(&left);
        this->right = shared_ptr<cluster>(&right);
    }
};
int main() {
    cluster left;
    cluster right;
    cluster father(left,right);
    return 0;
}

struct cluster {
    shared_ptr<cluster> left,right;
    weak_ptr<cluster> father;
    cluster(){}
    cluster(shared_ptr<cluster>& left,shared_ptr<cluster>& right) {
        right->father = left->father = this;