void
RBTREE_REMOVE_NODE(struct RBTREE_TYPENAME* target, struct RBTREE_NODE* N)
{
DEBUG_RBTREE("rbtree_remove_node: "RBTREE_KEY_PRNF"\n",
RBTREE_KEY_PRNA(N->key));
valgrind_assert(target->size >= 1);
DEBUG_RBTREE("before:\n");
// RBTREE_PRINT(target);
if (target->size == 1)
{
valgrind_assert(target->root == N);
target->root = 0;
goto end;
}
// If N has two children, we use replacement R: in-order successor
{
struct RBTREE_NODE* R = NULL;
if (N->right != NULL && N->left != NULL)
R = rbtree_leftmost_loop(N->right);
if (R != NULL)
swap_nodes(target, N, R);
delete_one_child(target, N);
DEBUG_RBTREE("after:\n");
// RBTREE_PRINT(target);
}
end:
target->size--;
}
void rb_delete(rb_node* n, rb_tree* tree) {
#ifdef DEBUG
if(!is_leaf(n->left, tree))
assert(is_leaf(n->right, tree));
if(!is_leaf(n->right, tree))
assert(is_leaf(n->left, tree));
#endif
delete_one_child(n, tree);
tree->n--;
}
void delete_one_child(ptr_rbnode node) {
ptr_rbnode s = get_sibiling(node), p = node->parent;
if (p) {
if (s->color == RED) {
p->color = RED; s->color = BLACK;
if (p->left == node) {
rotate_left(p);
}
else {
rotate_right(p);
}
}
s = get_sibiling(node), p = node->parent;
if (s->color == BLACK && s->left->color == BLACK && s->right->color == BLACK) {
if (p->color == BLACK) {
s->color = RED;
delete_one_child(p);
}
else {
s->color = RED;
p->color = BLACK;
}
}
else {
if (node->parent->left == node && s->right->color == RED) {
s->color = p->color; p->color = BLACK; s->right->color = BLACK;
rotate_left(p);
}
else if (node->parent->left == node && s->left->color == RED) {
s->left->color = p->color; p->color = BLACK;
rotate_right(s);
rotate_left(s->parent->parent);
}
else if (node->parent->right == node && s->left->color == RED) {
s->color = p->color; p->color = BLACK; s->left->color = BLACK;
rotate_right(p);
}
else if (node->parent->right == node && s->right->color == RED) {
s->right->color = p->color; p->color = BLACK;
rotate_left(s);
rotate_right(s->parent->parent);
}
else
assert(0 && "balance error");
}
}
}
ptr_rbnode delete_node(ptr_rbnode root, rbtree_element_type_t val, int logging) {
ptr_rbnode node = find_node(root, val);
if (node) {
ptr_rbnode left_max_node = NULL;
if (node->left->nil == 0 && node->right->nil == 0) {
left_max_node = find_max_node(node->left);
node->val = left_max_node->val;
node = left_max_node;
}
ptr_rbnode child = node->right->nil == 1 ? node->left : node->right;
if (node->color == BLACK) {
node->color = child->color;
delete_one_child(node);
}
root = replace_node(root, child, node);
free(node);
return root;
}
else {
if (logging) printf("%d is not in the tree\n", val);
return root;
}
}