NodeT *balancing(NodeT *p)
{
preorderEchilibru(p);
NodeT *w;
if(p->ech==-2)
{
w=p->left;
if(w->ech==1)
{
p=doubleRotationRight(p);
}
else
{
p=simpleRotationRight(p);
}
}
else if(p->ech==2)
{
w=p->right;
if(w->ech==-1)
{
p=doubleRotationLeft(p);
}
else
{
p=simpleRotationLeft(p);
}
}
return p;
}
/**
* Fixes a tree configuration by rotations.
* - If a node has a inverse balance in relation to
* his parent after the insertion, a double rotation
* on parent must be done. The direction depends only
* of the balance.
* - If both has the same balance signal, a single rotation
* on unbalanced node must be done.
* @param node
* @return
*/
Node *fix(Node* node) {
if (node != NULL) {
if (node->balance >= 2) {
if (node->left && node->left->balance > 0) {
cout << "Rotacao simples a direita no node " << node->info << endl;
node = singleRotationRight(node);
} else {
cout << "Rotacao dupla a direita no node " << node->info << endl;
node = doubleRotationRight(node);
}
} else if (node->balance <= -2) {
if (node->right && node->right->balance < 0) {
cout << "Rotacao simples a esquerda no node " << node->info << endl;
node = singleRotationLeft(node);
} else {
cout << "Rotacao dupla a esquerda no node " << node->info << endl;
node = doubleRotationLeft(node);
}
}
resetHeightAndBalance(node);
node->left = fix(node->left);
node->right = fix(node->right);
}
return node;
}
