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);
}
}
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 * rotateRL (Tree * tree) {
Tree * r = tree -> right;
Tree * rl = tree -> right -> left;
Tree * rlr = tree -> right -> left -> right;
tree -> right = rl;
tree -> right -> right = r;
tree -> right -> right -> left = rlr;
tree = rotateRR(tree);
return tree;
}
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);
}
}
}
