/*
* Delete node 'z' from the tree and return its data pointer.
*/
void *rbtree_delete(struct rbtree *tree, struct rbnode *z)
{
struct rbnode *x, *y;
void *data = z->data;
if (z->left == rbnil(tree) || z->right == rbnil(tree)) {
y = z;
} else {
y = rbsuccessor(tree, z);
}
x = (y->left == rbnil(tree)) ? y->right : y->left;
if ((x->parent = y->parent) == rbtree_root(tree)) {
rbtree_first(tree) = x;
} else {
if (y == y->parent->left) {
y->parent->left = x;
} else {
y->parent->right = x;
}
}
if (y->color == black) {
rbrepair(tree, x);
}
if (y != z) {
y->left = z->left;
y->right = z->right;
y->parent = z->parent;
y->color = z->color;
z->left->parent = z->right->parent = y;
if (z == z->parent->left) {
z->parent->left = y;
} else {
z->parent->right = y;
}
}
free(z);
tree->num_nodes--;
return (data);
}
/*
* Delete node 'z' from the tree and return its data pointer.
*/
void *rbdelete(struct rbtree *tree, struct rbnode *z)
{
struct rbnode *x, *y;
void *data = z->data;
if (z->left == rbnil(tree) || z->right == rbnil(tree))
y = z;
else
y = rbsuccessor(tree, z);
x = (y->left == rbnil(tree)) ? y->right : y->left;
if ((x->parent = y->parent) == rbroot(tree)) {
rbfirst(tree) = x;
} else {
if (y == y->parent->left)
y->parent->left = x;
else
y->parent->right = x;
}
if (y->color == black)
rbrepair(tree, x);
if (y != z) {
y->left = z->left;
y->right = z->right;
y->parent = z->parent;
y->color = z->color;
z->left->parent = z->right->parent = y;
if (z == z->parent->left)
z->parent->left = y;
else
z->parent->right = y;
}
free(z);
return data;
}
