参照物 一文读懂 AVL 树(5)
y->left = rr_rotate(x);
return ll_rotate(y);
}
Node * AVL::rl_rotate(Node * y)
{
Node * x = y->right;
y->right = ll_rotate(x);
return rr_rotate(y);
}
void AVL::destroy(Node * node)
{
if (node == nullptr)
return;
destroy(node->left);
destroy(node->right);
delete node;
}
int AVL::get_height(Node * node)
{
if (node == nullptr)
return 0;
return node->height;
}
int AVL::get_balance(Node * node)
{
if (node == nullptr)
return 0;
return get_height(node->left) - get_height(node->right);
}
Node * AVL::insert_real(int key, Node * node)
{
if (node == nullptr)
return new Node(key);
if (key < node->key)
node->left = insert_real(key, node->left);
else if (key > node->key)
node->right = insert_real(key, node->right);
else
return node;
node->height = max(get_height(node->left), get_height(node->right)) + 1;
int balance = get_balance(node);
// 左左失衡
if (balance > 1 && get_balance(node->left) > 0)
return ll_rotate(node);
// 右右失衡
if (balance < -1 && get_balance(node->right) < 0)
return rr_rotate(node);
// 左右失衡
if (balance > 1 && get_balance(node->left) < 0)
return lr_rotate(node);
// 右左失衡
if (balance < -1 && get_balance(node->right) > 0)
return rl_rotate(node);
return node;
}
Node * AVL::find_real(int key, Node * node)
{
if (node == nullptr)
return nullptr;
if (key < node->key)
return find_real(key, node->left);
else if (key > node->key)
return find_real(key, node->right);
它就是在展示一个“警告中国”的姿态