static void avl_free_node(avl_node_t *root)
{
if(root == NULL)
return;
avl_free_node(root->left_child);
avl_free_node(root->right_child);
bs_free(root);
}
void bs_avl_deinit(bs_avl_t* avl)
{
avl_node_t* node;
if(NULL == avl->root)
{
return ;
}
avl_free_node((avl_node_t*)avl->root);
}
/* delete an node from tree */
static avl_node_t* avl_remove_node(avl_node_t* root, avl_key_t key)
{
int factor = 0;
int rotate = 0;
if (root == NULL)
return NULL;
if (key < root->key)
{
root->left = avl_remove_node(root->left, key);
}
else if (key > root->key)
{
root->right = avl_remove_node(root->right, key);
}
else /* this is the node to be deleted */
{
if ((root->left == NULL) || (root->right == NULL))
{
avl_node_t* node = (root->left ? root->left : root->right);
if (node != NULL) /* one child case */
{
*root = *node;
}
else /* no child case */
{
node = root;
root = NULL;
}
avl_free_node(node);
}
else /* node with two children */
{
avl_node_t* node = avl_node_min(root->right);
root->key = node->key;
root->data = node->data;
root->right = avl_remove_node(root->right, node->key);
}
}
if (root == NULL)
return NULL;
root->height = MAX(HEIGHT(root->left), HEIGHT(root->right)) + 1;
factor = avl_get_balance(root);
if (factor > 1)
{
int left_balance = avl_get_balance(root->left);
rotate = (left_balance >= 0 ? ROT_LEFT : ROT_RIGHT);
}
else if (factor < -1)
{
int right_balance = avl_get_balance(root->right);
rotate = (right_balance <= 0 ? ROT_RIGHT : ROT_LEFT);
}
return avl_balance_node(root, factor, rotate);
}
void
avl_free(avl_tree_t *root){
if(root == NULL){
return;
}
avl_free(root->left);
avl_free(root->right);
avl_free_node(root);
}
/* destroy all nodes */
static int avl_destroy_node(avl_node_t* root)
{
if (root->left != NULL)
return avl_destroy_node(root->left) + 1;
else if (root->right != NULL)
return avl_destroy_node(root->right) + 1;
else
{
avl_free_node(root);
return 1;
}
}
