void rb_delete(rbt *T, rbn *z)
{
rbn *x, *y = z;
COLOR y_original_color = y->color;
if (z->left == T->nil) {
x = z->right;
rb_transplant(T, z, z->right);
} else if (z->right == T->nil) {
x = z->left;
rb_transplant(T, z, z->left);
} else {
y = rb_minimum(T, z->right);
y_original_color = y->color;
x = y->right;
if (y->p == z)
x->p = y;
else {
rb_transplant(T, y, y->right);
y->right = z->right;
y->right->p = y;
}
rb_transplant(T, z, y);
y->left = z->left;
y->left->p = y;
y->color = z->color;
}
if (y_original_color == BLACK)
rb_delete_fixup(T, x);
}
static rb_node_t *rb_successor(rb_tree *tree,rb_node_t *x) {
rb_node_t *y;
if (x->right != tree->nil) {
return rb_minimum(tree, x->right);
}
y = x->parent;
while (y != tree->nil && x == y->right) {
x = y;
y = y->parent;
}
return y;
}
RBTree::Node *RBTree::rb_successor(Node *nd)
{
if(nd == NIL)
return NIL;
if(nd->right!=NIL)
return rb_minimum(nd->right);
while(nd->parent!=NIL && nd!=nd->parent->left)
nd = nd->parent;
return nd->parent;
}
rb_node_t* rb_successor(rb_node_t* nodex)
{
rb_node_t* nodey;
if(nodex->rchild != &nil)
{
return rb_minimum(nodex->rchild);
}
nodey = nodex->parent;
while (nodey != &nil && nodex == nodey->rchild)
{
nodex = nodey;
nodey = nodey->parent;
}
return nodey;
}
void
k_rbtree_delete(k_rbtree_t* t,k_rbnode_t* z)
{
/* y's postion is the really to be delete,
* move y to z's position and move x to y's postion
*/
k_rbnode_t* y = z;
k_rbnode_t* x = t->nil_node;
enum k_color_type_t y_old_color = y->color;
if(z->left == t->nil_node){//if one of z's child is nil move the other child to z;
x = z->right;
rb_transplant(t,z,z->right);
}else if(z->right == t->nil_node){
x = z->left;
rb_transplant(t,z,z->left);
}else{// y to be z's successor
y = rb_minimum(t,z->right);
y_old_color = y->color;
x = y->right;
//since y has no left child then move y's right to be y
if(y->parent == z){//move x to y's postion
x->parent = z;
}else{
rb_transplant(t,y,x);
y->right = z->right;
y->right->parent = y;
}
// move y to z's postion
rb_transplant(t,z,y);
y->left = z->left;
y->left->parent = y;
y->color = z->color;
}
if(y_old_color == k_color_black){
k_rbtree_delete_fixup(t,x);
}
}