node* __find_node_p (node* root, int data, node** parent) {
if (!root)
return root;
if (!root || data == root->data)
return root;
return data < root->data ? __find_node(root->lchild, data) : __find_node(root->rchild, data);
}
bool predecessor(const key_type& key, key_type* p) {
rb_tree_node* pos = __find_node(key);
if (!__isnil(pos) && !__isnil(pos = __predecessor(pos))) {
if (p != nullptr)
*p = pos->value.first;
return true;
}
return false;
}
bool erase(const key_type& key) {
rb_tree_node* pos = __find_node(key);
if (__isnil(pos))
return false;
rb_erase_result result = __bst_erase(pos);
// tree above garbage is legal.
if (result.first->color == black)
__rb_erase_fixup(result.second);
delete result.first;
return true;
}
bool contains(const key_type& key) const {
return !__isnil(__find_node(key));
}
node* find_node(bintree* tree, int data, node** parent) {
return __find_node(tree->root, data, parent);
}
node* __find_node (node* root, int data) {
if (!root || data == root->data)
return root;
return data < root->data ? __find_node(root->lchild, data) : __find_node(root->rchild, data);
}
