#include "AVLTree.hpp"
using namespace std;AVL_Tree::AVL_Tree(){this->root = NULL;
}void AVL_Tree::setRoot(Node *root){this->root = root;
}
Node *AVL_Tree::getRoot(){return this->root;
}/** height of tree or subtree** a node's height equals the max of node's left child's height and node's right child's height plus 1**parameters:1, node;//the node that we want to measure with**return: the height of the node*/
int AVL_Tree::height(Node *node){int h = -1;if (node != NULL) {int l_height = height(node->getLeft());int r_height = height(node->getRight());h = std::max(l_height,r_height) + 1;}return h;
}
/** the height difference of two children nodes**parameters:*          1, node;//the node which we want to know the differences of its two children**return: int; the height difference of the two children nodes*/int AVL_Tree::heightDiff(Node *node){int l_height = height(node->getLeft());int r_height = height(node->getRight());return l_height-r_height;}/***4 types of rotations**1)left left pattern*2)left right pattern*3)right right pattern*4)right left pattern**/
void AVL_Tree::ll_rotation(Node *node){int value = node->getData();Node *temp = node->getLeft();node->setData(temp->getData());node->setLeft(temp->getLeft());temp->setData(value);temp->setLeft(temp->getRight());temp->setRight(node->getRight());node->setRight(temp);}
void AVL_Tree::lr_rotation(Node *node){Node *temp = node->getLeft();node->setLeft(temp->getRight());temp->setRight(temp->getRight()->getLeft());node->getLeft()->setLeft(temp);ll_rotation(node);}
void AVL_Tree::rr_rotation(Node *node){int value = node->getData();Node *temp = node->getRight();node->setData(temp->getData());node->setRight(temp->getRight());temp->setData(value);temp->setRight(temp->getLeft());temp->setLeft(node->getLeft());node->setLeft(temp);}
void AVL_Tree::rl_rotation(Node *node){Node *temp = node->getRight();node->setRight(temp->getLeft());temp->setLeft(node->getRight()->getRight());node->getRight()->setRight(temp);rr_rotation(node);}/**Description: balancing the node whoes two children nodes' height difference is greater than 1 or smaller than -1**parameters:*          1, node;//the node which we want to rotate with, it is the polar point of the rotation***return: void****/
void AVL_Tree::balance(Node *node){int balance_factor = heightDiff(node);//differences of the node's two sub nodes.if (balance_factor>1) {//left side is heavyif (heightDiff(node->getLeft())>0) {//left left case
            ll_rotation(node);}else{//left right case
            lr_rotation(node);}}else if (balance_factor<-1){//right side heavyif (heightDiff(node->getRight())<0) {//right right case
            rr_rotation(node);}else{//right left case
            rl_rotation(node);}}
}/** Description: insert a node into the AVL tree and keep the whole structure balanced after inserting**Parameters:*          1, Node *node;//the node which needs to be inserted*          2, Node *root;//the root of the tree or subtree; **Return: Node *;//the parent node of the inserted node;*/Node *AVL_Tree::insert(Node *node, Node *root){if (this->root == NULL) {Node *root = new Node();root->setLeft(NULL);root->setRight(NULL);root->setData(node->getData());this->root = root;return root;}if (root == NULL) {return node;}else if(node->getData() < root->getData()){root->setLeft(insert(node, root->getLeft()));balance(root);}else if (node->getData()>=root->getData()){root->setRight(insert(node, root->getRight()));balance(root);}return root;
}/**Description: print out the sorted nodes of the AVL tree of AVL subtree**parameters:*          1, Node *node;//the root of the AVL tree of AVL subtree***/
void AVL_Tree::inorderSort(Node *node){if (node == NULL) {return;}inorderSort(node->getLeft());std::cout<<node->getData()<<" ";inorderSort(node->getRight());}