Method deleteInternal

templates/red-black-tree.cpp:338–369

    }

    void deleteInternal(RBTreeNode* z)
    {
        auto y = z;
        auto origin_color = y->color;
        RBTreeNode* x = nullptr;

        if (z->left == nil) {
            x = z->right;
            transplant(z, z->right);
        } else if (z->right == nil) {
            x = z->left;
            transplant(z, z->left);
        } else {
            y = treeMinimum(z->right);
            origin_color = y->color;
            x = y->right;
            if (y->p == z) {
                x->p = y;
            } else {
                transplant(y, y->right);
                y->right = z->right;
                y->right->p = y;
            }
            transplant(z, y);
            y->left = z->left;
            y->left->p = y;
            y->color = z->color;
        }
        if (origin_color == BLACK) {
            deleteFixUp(x);
        }
    }

    void remove(int k)
    {