二叉排序树的实现

来源：互联网发布：apache服务器搭建编辑：程序博客网时间：2024/06/06 00:32

问题表述：
二叉排序树，如果左子树不为空，那么左子树上所有节点的值均小于其根结点的值；如果右子树不为空，那么右子树所有节点的值均大于其根结点的值；左右子树也分别为二叉排序树。

代码实现：

class Node{    public int data;    public Node left;    public Node right;    public Node(int data){        this.data = data;        this.left = null;        this.right = null;    }}public class BinaryTree {    private Node root;    public BinaryTree(){        root = null;    }    //insert    public void insert(int data) {        Node newnode = new Node(data);        if (root==null) {            root = newnode;        }else {            Node current = root;            Node parent;            while (true) {                parent = current;                if (data<current.data) {                    current = current.left;                    if (current==null) {                        parent.left = newnode;                        return;                    }                }else {                    current = current.right;                    if (current==null) {                        parent.right = newnode;                        return;                    }                }            }        }    }    //build    public void buildTree(int[] data) {        for (int i = 0; i < data.length; i++) {            insert(data[i]);        }    }    //inOrder    public void inOrder(Node localRoot) {        if (localRoot!=null) {            inOrder(localRoot.left);            System.out.print(localRoot.data+" ");            inOrder(localRoot.right);        }    }    public void inOder() {        inOrder(this.root);    }    //preOrder    public void preOrder(Node localRoot) {        if (localRoot!=null) {            System.out.print(localRoot.data+" ");            preOrder(localRoot.left);            preOrder(localRoot.right);        }    }    private void preOrder() {        preOrder(this.root);    }    //postOrder    public void postOrder(Node localRoot) {        if (localRoot!=null) {            postOrder(localRoot.left);            postOrder(localRoot.right);            System.out.print(localRoot.data+" ");        }    }    public void postOrder() {        postOrder(this.root);    }    public static void main(String[] args) {        BinaryTree binaryTree = new BinaryTree();        int[] data = {2,8,7,4,9,3,1,6,7,5};        binaryTree.buildTree(data);        System.out.print("inOrder is: ");        binaryTree.inOder();        System.out.println();        System.out.print("preOrder is: ");        binaryTree.preOrder();        System.out.println();        System.out.print("postOrder is: ");        binaryTree.postOrder();        System.out.println();    }}

运行结果：
inOrder is: 1 2 3 4 5 6 7 7 8 9
preOrder is: 2 1 8 7 4 3 6 5 7 9
postOrder is: 1 3 5 6 4 7 7 9 8 2

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