void TreeBST::del(Node* p) {
    if (empty()) {
        cout << "Drzewo puste" << endl;
        return;
    }

    if (empty(p->left()) && empty(p->right())) {
        if (p == root) {
            delete p;
            root = NULL;
            return;
        }

        if (p->parent()->left() == p) {
            p->parent()->setLeft(NULL);
            delete p;
            return;
        }
        else {
            p->parent()->setRight(NULL);
            delete p;
            return;
        }
    }
    else if (!empty(p->left()) && empty(p->right())) {
        if (p == root) {
            root = p->left();
            delete p;
            return;
        }

        if (p->parent()->left() == p) {
            p->parent()->setLeft(p->left());
            p->left()->setParent(p->parent());
            delete p;
            return;
        }
        else {
            p->parent()->setRight(p->left());
            p->left()->setParent(p->parent());
            delete p;
            return;
        }

    }
    else if (!empty(p->right()) && empty(p->left())) {
        if (p == root) {
            root = p->right();
            delete p;
            return;
        }

        if (p->parent()->left() == p) {
            p->parent()->setLeft(p->right());
            p->right()->setParent(p->parent());
            delete p;
            return;
        }
        else {
            p->parent()->setRight(p->right());
            p->right()->setParent(p->parent());
            delete p;
            return;
        }
    }
    else {
        Node* succNode = succ(p);

        if (p->right() != succNode) {
            p->right()->setParent(succNode);
        }

        if (succNode->parent() != p) {
            if (succNode->parent()->left() == succNode) {
                if (!empty(succNode->left())) {
                    succNode->parent()->setLeft(succNode->left());
                }
                else {
                    succNode->parent()->setLeft(succNode->right());
                }
            }
            else {
                if (!empty(succNode->right())) {
                    succNode->parent()->setRight(succNode->left());
                }
                else {
                    succNode->parent()->setRight(succNode->right());
                }
            }
        }
        if (p != root) {
            if (p->parent()->left() == p) {
                p->parent()->setLeft(succNode);
            }
            else {
                p->parent()->setRight(succNode);
            }
        }
        else {
            root = succNode;
        }
        succNode->setLeft(p->left());
        if (p->right() != succNode)
            succNode->setRight(p->right());
        succNode->setParent(NULL);

        delete p;
        return;
    }
}