public class AVLTreeDemo {
public static void main(String[] args) {
// int []arr=new int[]{4,3,6,5,7,8};
int []arr=new int[]{10,12,8,9,7,6};
AVLTree avlTree = new AVLTree();
for (int i = 0; i < arr.length; i++) {
avlTree.add(new Node(arr[i]));
}
int height = avlTree.getRoot().height();
int rightHeight = avlTree.getRoot().rightHeight();
int leftHeight = avlTree.getRoot().leftHeight();
System.out.println(height);
System.out.println(rightHeight);
System.out.println(leftHeight);
}
}
class AVLTree{
Node root;
//
public Node getRoot() {
return root;
}
public void add(Node node){
if (this.root==null){
root=node;
}else {
this.root.add(node);
}
}
public void fixOrders(){
if (this.root==null){
System.out.println("二叉树为空");
}else {
this.root.fixOrder();
}
}
public Node searchNode(int value){
if (root!=null){
return root.searchNode(value);
}else{
System.out.println("二叉树为空");
}
return null;
}
public Node searchParent(int value){
if (root==null){
System.out.println("二叉树为空");
}else {
return root.seacherParent(value);
}
return null;
}
public int deleteRight(Node node){
Node target=node;
while (target.left!=null){
target=target.left;
}
deleteNode(target.value);
return target.value;
}
public void deleteNode(int value){
if (root==null){
return;
}else {
Node targetNode = searchNode(value);
if (targetNode==null){
return;
}
if (root.left==null&&root.right==null){
root=null;
return;
}else {
Node parentNode = searchParent(value);
if (targetNode.left==null&&targetNode.right==null){
if (parentNode.left!=null&&parentNode.left.value==value){
parentNode.left=null;
}else if (parentNode.right!=null&&parentNode.right.value==value){
parentNode.right=null;
}
}else if(targetNode.left!=null&&targetNode.right!=null){//删除有两个子点的节点
//最小节点与要删除的节点
int minValue = deleteRight(targetNode.right);//也可以从目标节点左子树找最小的
targetNode.value=minValue;
}else {//删除只有一颗子节点的节点
//如果要删除的节点有左子节点
if (targetNode.left!=null){
if (parentNode!=null){
if (parentNode.left.value==value){
parentNode.left=targetNode.left;
}else {
parentNode.right=targetNode.left;
}
}else {
root=targetNode.left;
}
}else {
if (parentNode!=null){
if (parentNode.left.value==value){ //如果要删除的节点有右子节点
parentNode.left=targetNode.right;
}else {
parentNode.right=targetNode.right;
}
}else {
root=targetNode.right;
}
}
}
}
}
}
}
class Node{
Node left;
Node right;
int value;
public Node(int value) {
this.value = value;
}
public int height(){
return Math.max(left==null ? 0 : left.height(),right==null ? 0 :right.height())+1;
}
public int leftHeight(){
if (left==null){
return 0;
}else {
return left.height();
}
}
public int rightHeight(){
if (right==null){
return 0;
}else {
return right.height();
}
}
public void leftRotate(){
Node newNode = new Node(this.value);//新建一个节点
newNode.left=this.left;//新建节点的左子节点为当前节点的左节点
newNode.right=this.right.left;//新建节点的右子节点为当前节点的右子节点
//以上相当于构建了一颗新的二叉树
//以下则是将其连上旧的二叉树
this.value=right.value;//用当前节点的右节点替换当前节点的值
this.right=this.right.right;//把当前节点的右子树往上提一下
this.left=newNode;//把当前节点左树连上新节点的树
}
public void rightRotate(){
Node newNode = new Node(this.value);
newNode.right=this.right;
newNode.left=this.left.right;
this.value=left.value;
this.left=this.left.left;
this.right=newNode;
}
public Node searchNode(int value){
if (this.value==value){
return this;
}
else if (value<this.value){
if (this.left!=null){
return this.left.searchNode(value);
}
}else {
if (this.right!=null){
return this.right.searchNode(value);
}
}
return null;
}
public Node seacherParent(int value){
//如果当前节点是要删除的节点的父节点，就返回
if (this.left!=null&&this.left.value==value||this.right!=null&&this.right.value==value){
return this;
}if (this.right!=null&&value>this.value){
return this.right.seacherParent(value);
}if (this.left!=null&&value<=this.value){//要查找的节点小于当前节点往左子树递归查找
return this.left.seacherParent(value);
}
return null;
}
public void add(Node node){
if (node.value<this.value){
if (this.left==null){
this.left=node;
}else {
this.left.add(node);
}
}else {
if (this.right==null){
this.right=node;
}else {
this.right.add(node);
}
}
if(rightHeight()-leftHeight()>1){
if (this.right.leftHeight()>this.right.rightHeight()){
this.right.rightRotate();
leftRotate();
}else {
leftRotate();
}
}else if (leftHeight()-rightHeight()>1){
if (this.left.rightHeight()>this.left.leftHeight()){
this.left.leftRotate();
rightRotate();
}else {
rightRotate();
}
}
}
public void fixOrder(){//中序遍历
if (this.left!=null){
this.left.fixOrder();
}
System.out.println(this);
if (this.right!=null){
this.right.fixOrder();
}
}
@Override
public String toString() {
return "Node{" +
"value=" + value +
'}';
}
}