void AVLTree<K, V>::insert(Node* & subtree, const K & key, const V & value)
{
if(subtree == NULL) {
subtree = new Node(key, value);
return;
}
if(subtree->key == key) return;
if(key < subtree->key) {
insert(subtree->left, key, value);
} else {
insert(subtree->right, key, value);
}
if(heightOrNeg1(subtree->right) - heightOrNeg1(subtree->left) == 2) {
if(subtree->right != NULL) {
if(heightOrNeg1(subtree->right->left) > heightOrNeg1(subtree->right->right)) {
rotateRightLeft(subtree);
} else if (heightOrNeg1(subtree->right->left) < heightOrNeg1(subtree->right->right)) {
rotateLeft(subtree);
}
}
} else if(heightOrNeg1(subtree->right) - heightOrNeg1(subtree->left) == -2) {
if(subtree->left != NULL) {
if(heightOrNeg1(subtree->left->right) > heightOrNeg1(subtree->left->left)) {
rotateLeftRight(subtree);
} else if(heightOrNeg1(subtree->left->right) < heightOrNeg1(subtree->left->left)) {
rotateRight(subtree);
}
}
}
subtree->height = calculateSubtreeHeight(subtree);
}
treeNode *reBalance(treeNode *nodeN) {
if (findHeight(nodeN->left) - findHeight(nodeN->right) > 1) {
if (findHeight(nodeN->left->left) > findHeight(nodeN->left->right)) {
nodeN = rotateRight(nodeN);
} else {
nodeN = rotateLeftRight(nodeN);
}
} else {
if (findHeight(nodeN->right) - findHeight(nodeN->left) > 1) {
if (findHeight(nodeN->right->right)
> findHeight(nodeN->right->left)) {
nodeN = rotateLeft(nodeN);
} else {
nodeN = rotateRightLeft(nodeN);
} /* else node is balanced */
}
}
return nodeN;
}
void AVLTree<K, V>::insert(Node* & subtree, const K & key, const V & value)
{
// your code here
// position found
if(subtree == NULL)
{
subtree = new Node(key, value);
return;
}
// duplicate key
if(key == subtree->key)
{
return;
}
// insert left
if(key < subtree->key)
{
// insert to the left recursively
insert(subtree->left, key, value);
// check balance
int balance = heightOrNeg1(subtree->right) - heightOrNeg1(subtree->left);
int left_balance = heightOrNeg1(subtree->left->right) - heightOrNeg1(subtree->left->left);
if(balance == -2)
{
if(left_balance == -1)
{
rotateRight(subtree);
}
else
{
rotateLeftRight(subtree);
}
}
subtree->height = 1+max( heightOrNeg1(subtree->left), heightOrNeg1(subtree->right) );
return;
}
// insert right
if(key > subtree->key)
{
// insert to the right recursively
insert(subtree->right, key, value);
// check balance
int balance = heightOrNeg1(subtree->right) - heightOrNeg1(subtree->left);
int right_balance = heightOrNeg1(subtree->right->right) - heightOrNeg1(subtree->right->left);
if(balance == 2)
{
if(right_balance == 1)
{
rotateLeft(subtree);
}
else
{
rotateRightLeft(subtree);
}
}
subtree->height = 1+max( heightOrNeg1(subtree->left), heightOrNeg1(subtree->right) );
}
}