void
rbtree_delete( rbtree_t *tree , rbtree_node_t *node )
{
uint_t red;
rbtree_node_t **root,*sentinel,*subst,*temp,*w;
/* a binary tree delete */
root = (rbtree_node_t **) &tree->root;
sentinel = tree->sentinel;
if (node->left == sentinel)
{
temp = node->right;
subst = node;
}
else if (node->right == sentinel)
{
temp = node->left;
subst = node;
}
else
{
subst = rbtree_min( node->right , sentinel );
if (subst->left != sentinel)
{
temp = subst->left;
}
else
{
temp = subst->right;
}
}
if (subst == *root)
{
*root = temp;
rbt_black( temp );
/* DEBUG stuff */
node->left = NULL;
node->right = NULL;
node->parent = NULL;
node->key = 0;
return;
}
red = rbt_is_red(subst);
if (subst == subst->parent->left)
{
subst->parent->left = temp;
}
else
{
subst->parent->right = temp;
}
if (subst == node)
{
temp->parent = subst->parent;
}
else
{
if (subst->parent == node)
{
temp->parent = subst;
}
else
{
temp->parent = subst->parent;
}
subst->left = node->left;
subst->right = node->right;
subst->parent = node->parent;
rbt_copy_color( subst , node );
if (node == *root)
{
*root = subst;
}
else
{
if (node == node->parent->left)
{
node->parent->left = subst;
}
else
{
node->parent->right = subst;
}
}
if (subst->left != sentinel)
{
subst->left->parent = subst;
}
if (subst->right != sentinel)
{
subst->right->parent = subst;
}
}
/* DEBUG stuff */
node->left = NULL;
node->right = NULL;
node->parent = NULL;
node->key = 0;
if (red)
{
return;
}
/* a delete fixup */
while (temp != *root && rbt_is_black(temp) )
{
if (temp == temp->parent->left)
{
w = temp->parent->right;
if (rbt_is_red(w) )
{
rbt_black( w );
rbt_red( temp->parent );
rbtree_left_rotate( root , sentinel , temp->parent );
w = temp->parent->right;
}
if (rbt_is_black(w->left) && rbt_is_black(w->right) )
{
rbt_red( w );
temp = temp->parent;
}
else
{
if (rbt_is_black(w->right) )
{
rbt_black( w->left );
rbt_red( w );
rbtree_right_rotate( root , sentinel , w );
w = temp->parent->right;
}
rbt_copy_color( w , temp->parent );
rbt_black( temp->parent );
rbt_black( w->right );
rbtree_left_rotate( root , sentinel , temp->parent );
temp = *root;
}
}
else
{
w = temp->parent->left;
if (rbt_is_red(w) )
{
rbt_black( w );
rbt_red( temp->parent );
rbtree_right_rotate( root , sentinel , temp->parent );
w = temp->parent->left;
}
if (rbt_is_black(w->left) && rbt_is_black(w->right) )
{
rbt_red( w );
temp = temp->parent;
}
else
{
if (rbt_is_black(w->left) )
{
rbt_black( w->right );
rbt_red( w );
rbtree_left_rotate( root , sentinel , w );
w = temp->parent->left;
}
rbt_copy_color( w , temp->parent );
rbt_black( temp->parent );
rbt_black( w->left );
rbtree_right_rotate( root , sentinel , temp->parent );
temp = *root;
}
}
}
rbt_black( temp );
}
ezRBTreeNode *rbtree_min_node(ezRBTree *tree) {
return rbtree_min(tree->root, tree->sentinel);
}