node* balanceNode(node* nod) {
node* newroot = NULL;
int bf = 0;
if(nod->left)
nod->left = balanceNode(nod->left);
if(nod->right)
nod->right= balanceNode(nod->right);
bf = balanceFactor(nod);
if(bf >= 2) {
if(balanceFactor(nod->left) <= -1 )
newroot = rotateLR(nod);
else
newroot = rotateLL(nod);
}else if(bf <= -2) {
if(balanceFactor(nod->right)<= 1)
newroot = rotateRL(nod);
else
newroot = rotateRR(nod);
}else
newroot = nod;
return(newroot);
}
Tree * balance (Tree * tree) {
if (tree -> nil)
return tree;
Balance balanced = balanceCase(tree);
switch (balanced) {
case Balanced:
tree -> left = balance(tree -> left);
tree -> right = balance(tree -> right);
return tree;
case LL:
ll++;
tree -> left = balance(tree -> left);
tree -> right = balance(tree -> right);
return rotateLL(tree);
case LR:
lr++;
tree -> left = balance(tree -> left);
tree -> right = balance(tree -> right);
return rotateLR(tree);
case RL:
rl++;
tree -> left = balance(tree -> left);
tree -> right = balance(tree -> right);
return rotateRL(tree);
case RR:
rr++;
tree -> left = balance(tree -> left);
tree -> right = balance(tree -> right);
return rotateRR(tree);
}
}
void AVL_Tree::balance(Node* city, int counter) {
Node* check;
while(city){
counter++;
if(city->getBalance() == 0)
break;
else if(city->getBalance() == 2){
check = city->getRight();
counter++;
if(city != m_root){
if(city -> getParent() -> getRight() == city)
city -> getParent() -> adjustBalance(-1);
else
city -> getParent() -> adjustBalance(1);
}
counter++;
if(check->getBalance()==-1)
rotateRL(city);
else
rotateLeft(city);
city -> setBalance(0);
check -> setBalance(0);
}
else if(city -> getBalance() == -2){
counter++;
if(city != m_root){
counter++;
if(city -> getParent() -> getRight() == city)
city -> getParent() -> adjustBalance(-1);
else
city -> getParent() -> adjustBalance(1);
}
check = city -> getLeft();
counter++;
if(check -> getBalance() == 1)
rotateLR(city);
else
rotateRight(city);
city -> setBalance(0);
check -> setBalance(0);
}
city = city -> getParent();
}
std::cout << "Comparison count for this function is " << counter << "\n";
}//end balance
void AVL_Tree::balance(Node* city) {
Node* check;
while(city){
if(city->getBalance() == 0)
break;
else if(city->getBalance() == 2){
check = city->getRight();
if(city != m_root){
if(city -> getParent() -> getRight() == city)
city -> getParent() -> adjustBalance(-1);
else
city -> getParent() -> adjustBalance(1);
}
if(check->getBalance()==-1)
rotateRL(city);
else
rotateLeft(city);
city -> setBalance(0);
check -> setBalance(0);
}
else if(city -> getBalance() == -2){
if(city != m_root){
if(city -> getParent() -> getRight() == city)
city -> getParent() -> adjustBalance(-1);
else
city -> getParent() -> adjustBalance(1);
}
check = city -> getLeft();
if(check -> getBalance() == 1)
rotateLR(city);
else
rotateRight(city);
city -> setBalance(0);
check -> setBalance(0);
}
city = city -> getParent();
}
}//end balance
void balanceCheck(struct node *root){
if ( getHeight(root->left) > (getHeight(root->right) + 1) ){
printf("Imbalance! The Right sub-tree of node %d is taller!\n",root->value);
if ( getHeight(root->left->right) > (getHeight(root->left->left)) ){
printf("Rotating using LR Rotation...\n");
rotateLR(root);
} else {
printf("Rotating using LL Rotation...\n");
rotateLL(root);
}
} else if ( getHeight(root->right) > (getHeight(root->left) + 1) ){
printf("Imbalance! The Right sub-tree of node %d is taller!\n",root->value);
if ( getHeight(root->right->left) > (getHeight(root->right->right)) ){
printf("Rotating using RL Rotation...\n");
rotateRL(root);
} else {
printf("Rotating using RR Rotation...\n");
rotateRR(root);
}
}
}