void Binary_search_tree::remove_helper(int x, BST_node* t, BST_node* p) {
if (t != nullptr){
if (x > t->get_data()) {
remove_helper(x, t->get_right_child(), t);
} else if (x < t->get_data()) {
remove_helper(x, t->get_left_child(), t);
} else {
remover(t, p);
}
}
}
void Binary_search_tree::remover(BST_node* t, BST_node* p) {
if (t->get_left_child() == nullptr) {
if (t->get_right_child() == nullptr) {
if (t->get_data() < p->get_data()) {
delete t;
p->set_left_child(nullptr);
} else {
delete t;
p->set_right_child(nullptr);
}
} else {
t->set_data(get_min(t->get_right_child())->get_data());
remove_helper(get_min(t->get_right_child())->get_data(), t->get_left_child(), t);
remove_helper(get_min(t->get_right_child())->get_data(), t->get_right_child(), t);
}
} else {
t->set_data(get_max(t->get_left_child())->get_data());
remove_helper(get_max(t->get_left_child())->get_data(), t->get_left_child(), t);
remove_helper(get_max(t->get_left_child())->get_data(), t->get_right_child(), t);
}
}
void Q3ButtonGroup::remove(QAbstractButton *button)
{
fixChildren();
remove_helper(button);
}
int Q3ButtonGroup::insert(QAbstractButton *button, int id)
{
remove_helper(button);
return insert_helper(button, id);
}
bool ChangeSet::remove(int start, int end)
{ return remove_helper(start, end - start); }
void AVLTree::remove_helper(Node * & t, const std::string& name) {
if( t == NULL ) return; // wasn't able to find the node
else if(name < t->city.name) {
remove_helper( t->left, name );
}
else if(name > t->city.name) {
remove_helper( t->right, name );
}
else { // else found the node
// found the node to delete
// Case 1: node has no children
if((!t->left) && (!t->right)) {
delete t;
t = NULL;
}
// Case 2a: node has 1 child on left
else if(!t->right) {
Node * save_left = t->left;
delete t;
t = save_left;
}
//Case 2b: node has 1 child on right
else if(!t->left) {
Node * save_right = t->right;
delete t;
t = save_right;
}
// Case 3: node has 2 children
else {
// find the inorder successor, left most child of right subtree
Node * succ = t->right;
// case 1: succ has no left child
if(!succ->left) {
delete t;
t = succ;
}
// case 2: succ does have left child
else {
while(succ->left) succ = succ->left;
Node * save_right = succ->right;
t->city = succ->city;
delete succ;
succ = save_right;
}
}
}
if(!t) return;
t->height = MAX( height(t->left), height(t->right) ) + 1;
const int balance = getBalance( t );
const int balance_left = getBalance( t->left );
const int balance_right = getBalance( t->right );
// Case 1: Left Left Case
if((balance > 1) && (balance_left >= 0)) {
rotateWithLeftChild(t);
}
// Case 2: Left Right Case
else if((balance > 1) && (balance_left < 0)) {
rotateWithRightChild(t->left);
rotateWithLeftChild(t);
}
// Case 3: Right Right
else if((balance < -1) && (balance_right <= 0)) {
rotateWithRightChild(t);
}
// Case 4: Right Left
else if((balance < -1) && (balance_right > 0)) {
rotateWithLeftChild(t->right);
rotateWithRightChild(t);
}
}
void AVLTree::remove(const std::string& name) {
remove_helper(root, name);
}
void Binary_search_tree::remove(int x) {
remove_helper(x, root, nullptr);
}