Java-线索二叉树的实现

概念性的东西，自行百度。

按照国际管理，直接上代码来分析。

1、Node节点类

package com.tree.thread;/** * Author: lihao * Date：2017/8/30 * Description:ThreadBinaryTree Node */public class Node{    private int data;    private Node left;    private boolean leftIsThread;        // 左孩子是否为线索    private Node right;    private boolean rightIsThread;       // 右孩子是否为线索    public Node(int data)    {        this.data = data;        this.left = null;        this.leftIsThread = false;        this.right = null;        this.rightIsThread = false;    }    public int getData()    {        return data;    }    public void setData(int data)    {        this.data = data;    }    public Node getLeft()    {        return left;    }    public void setLeft(Node left)    {        this.left = left;    }    public boolean isLeftIsThread()    {        return leftIsThread;    }    public void setLeftIsThread(boolean leftIsThread)    {        this.leftIsThread = leftIsThread;    }    public Node getRight()    {        return right;    }    public void setRight(Node right)    {        this.right = right;    }    public boolean isRightIsThread()    {        return rightIsThread;    }    public void setRightIsThread(boolean rightIsThread)    {        this.rightIsThread = rightIsThread;    }    @Override    public boolean equals(Object obj)    {        if (obj instanceof Node)        {            Node temp = (Node) obj;            if (temp.getData() == this.data)            {                return true;            }        }        return false;    }    @Override    public int hashCode()    {        return super.hashCode() + this.data;    }}

2、创建二叉树、二叉树中序线索化(线索化有3种，此处单讲中序)

package com.tree.thread;public class ThreadTree {    private Node root;         // 根节点    private Node pre = null;   // 线索化的时候保存前驱    public ThreadTree() {        this.root = null;        this.pre = null;    }    public ThreadTree(int[] data) {        this.pre = null;        this.root = createTree(data, 0);   // 创建二叉树    }    /**     * 创建二叉树     */    public Node createTree(int[] data, int index) {        if (index >= data.length) {            return null;        }        Node node = new Node(data[index]);        node.setLeft(createTree(data, 2 * index + 1));        node.setRight(createTree(data, 2 * index + 2));        return node;    }    /**     * 将以root为根节点的二叉树线索化  中序法     */    public void inThread(Node root) {        if (root != null) {            inThread(root.getLeft());     // 线索化左孩子            if (null == root.getLeft())   // 左孩子为空            {                root.setLeftIsThread(true);    // 将左孩子设置为线索                root.setLeft(pre);            }            if (pre != null && null == pre.getRight())  // 右孩子为空            {                pre.setRightIsThread(true);                pre.setRight(root);            }            pre = root;                 //每次将当前节点设置为pre            inThread(root.getRight());       // 线索化右孩子        }    }    /**     * 中序遍历线索二叉树     */    public void inThreadList(Node root) {        if (root == null) {            return;        }        //查找中序遍历的起始节点        while (root != null && !root.isLeftIsThread()) {            root = root.getLeft();        }        while (root != null) {            System.out.print(root.getData() + ",");            if (root.isRightIsThread())   // 如果右孩子是线索            {                root = root.getRight();            } else         // 有右孩子            {                root = root.getRight();                while (root != null && !root.isLeftIsThread()) {                    root = root.getLeft();                }            }        }    }    /**     * 中序遍历     */    public void inList(Node root) {        if (root != null) {            inList(root.getLeft());            System.out.print(root.getData() + ",");            inList(root.getRight());        }    }    public Node getRoot() {        return root;    }    public void setRoot(Node root) {        this.root = root;    }}