static void rb_tree_delete(rb_tree_t *tree, rb_tree_node_t *z)
{
rb_tree_node_t *y = NULL;
rb_tree_node_t *x = NULL;
if (IS_NIL(tree, z->left) || IS_NIL(tree, z->right)) {
y = z;
} else {
y = rb_tree_successor(tree, z);
}
if (IS_NIL(tree, y->left)) {
x = y->right;
} else {
x = y->left;
}
x->parent = y->parent;
if (IS_NIL(tree, y->parent)) {
tree->head = x;
} else {
if (y == y->parent->left) {
y->parent->left = x;
} else {
y->parent->right = x;
}
}
if (y != z) {
/* z->left = y->left; */
/* z->right = y->right; */
/* z->parent = y->parent; */
/* z->color = y->color; */
z->key = y->key;
z->count = y->count;
}
if (y->color == BLACK) {
rb_tree_delete_fixup(tree, x);
}
free(y);
}
void rb_tree_delete (RBTREE *T , NODE *z) {
NODE *y = z;
NODE *x;
int y_original_color = y->color;
if (z->left == T->nil) {
x = z->right;
transplant (T , z , z->right);
free (z);
}else if (z->right == T->nil) {
x = z->right;
transplant (T , z , z->left);
free (z);
}else {
y = minimum_rb_tree (T , z->right);
y_original_color = y->color;
x = y->right;
if (y->parent == z) {
x->parent = y;
transplant (T , z , y);
y->left = z->left;
z->left->parent = y;
y->color = z->color;
free (z);
}else {
transplant (T , y , y->right);
y->right = z->right;
y->right->parent = y;
transplant (T , z , y);
y->left = z->left;
y->left->parent = y;
y->color = z->color;
free (z);
}
}
if (y_original_color == BLACK)
rb_tree_delete_fixup (T , x);
}
