我不知道这个的解决方案，一个AVLTREE的程序如何解决错误error: cannot find symbol node = rotateWithRightChild(node);

Question

这是我程序的代码，它是一个 AVL 树，但它显示错误 error: cannot find symbol 此错误消息表明编译器找不到符号 rotateWithRightChild。当当前范围内未定义方法或变量时，通常会发生这种情况。

导入java.util.Scanner；

class Node
{
    int element;
    int h;
    Node leftChild;
    Node rightChild;
    
    public Node()
    {
        leftChild = null;
        rightChild = null;
        element = 0;
        h = 0;
    }
    
    public Node(int element)
    {
        leftChild = null;
        rightChild = null;
        this.element = element;
        h = 0;
    }
}

class ConstructAVLTree
{ 
   private Node rootNode;
   
   public ConstructAVLTree()
   {
    rootNode = null;
   }
   
   public void removeAll()
   {
     rootNode = null;
   }
   
   public boolean checkEmpty()
   {
     if(rootNode == null)
        return true;
        else
            return false;
   }
   
   public void insertElement(int element)
   {
    rootNode = insertElement (element, rootNode);
   }
   
   private int getHeight(Node node)
   {
    return node == null ?-1 : node.h;
   }
   
   private int getMaxHeight(int leftNodeHeight, int rightNodeHeight)
   {
    return leftNodeHeight > rightNodeHeight ? leftNodeHeight : rightNodeHeight;
   }
   
   private Node insertElement(int element, Node node)
   {
    if (node== null)
        node = new Node(element);
            else if (element < node.element)
            {
                node.leftChild = insertElement( element, node.leftChild);
                if (getHeight(node.leftChild)- getHeight(node.rightChild) == 2)
                    if (element < node.leftChild.element)
                        node = rotateWithLeftChild(node);
                        else
                            node = doubleWithLeftChild(node);
            }
            else if ( element > node.element)
            {
                node.rightChild = insertElement( element, node.rightChild);
                if (getHeight(node.rightChild)- getHeight(node.leftChild) == 2)
                    if (element > node.rightChild.element)
                        node = rotateWithRightChild(node);
                        else
                            node = doubleWithRightChild(node);
                
            }
            else
                node.h = getMaxHeight(getHeight(node.leftChild), getHeight(node.rightChild))+1;
                
                return node;
   }
   
   private Node rotateWithLeftChild(Node node2)
   {
      Node node1 = node2.leftChild;
      node2.leftChild = node1.rightChild;
      node1.rightChild = node2;
      node2.h = getMaxHeight( getHeight(node2.leftChild), getHeight(node2.rightChild)) + 1;
      node1.h = getMaxHeight( getHeight(node1.leftChild), node2.h) + 1;
      return node1;
   }
   private Node doubleWithLeftChild(Node node3)
   {
   
    node3.leftChild = rotateWithRightChild( node3.leftChild);
    return rotateWithLeftChild (node3);
   }
   
   private Node doubleWithRightChild( Node node1)
   {
    node1.rightChild = rotateWithLeftChild( node1.rightChild);
    return rotateWithRightChild(node1);
   }
   
   public int getTotalNumberOfNodes()
   {
     return getTotalNumberOfNodes(rootNode);
   }
   private int getTotalNumberOfNodes(Node head)
   {
    if (head==null)
        return 0;
        else
        {
            int length = 1;
            length = length + getTotalNumberOfNodes(head.leftChild);
            length = length + getTotalNumberOfNodes(head.rightChild);
            return length;
        }
   }
   public boolean searchElement(int element)
   {
    return searchElement(rootNode, element);
   }
   
   private boolean searchElement(Node head, int element)
   {
    boolean check = false;
    while ((head != null) && !check)
    {
        int headElement = head.element;
        if ( element < headElement)
            head = head.leftChild;
            else if (element > headElement)
                head = head.rightChild;
                else
                {
                    check = true;
                    break;
                }
                check = searchElement(head, element);
    }
    return check;
    }
    
    public void inorderTraversal()
    {
        inorderTraversal(rootNode);
    }
    private void inorderTraversal(Node head)
    {
        if (head != null);
        {
            inorderTraversal(head.leftChild);
                System.out.print(head.element+ "");
                inorderTraversal(head.rightChild);
        }
    }
    
    public void preorderTraversal()
    {
        preorderTraversal(rootNode);
    }
    private void preorderTraversal(Node head)
    {
        if (head != null)
        {
            System.out.print(head.element + "");
                preorderTraversal(head.leftChild);
                preorderTraversal(head.rightChild);
        }
    }
    
    public void postorderTraversal()
    {
        postorderTraversal(rootNode);
    }
    
    private void postorderTraversal(Node head)
    {
        if (head!= null)
    
        {
            postorderTraversal(head.leftChild);
            postorderTraversal(head.rightChild);
            System.out.print(head.element+ "");
        }
    }
    
    
   }

    

      error: cannot find symbol "node = rotateWithRightChild(node);"

Answer 1

您的代码仅定义方法

rotateWithLeftChild

。请添加方法

rotateWithRightChild

.

Answer 2

你必须在java中使用

new

关键字来创建一个实例。

Object instance1 = new Object();