如何实现二叉排序树？

数据结构与算法

二叉树的递归定义：二叉树或者是一棵空树，或者是一棵由根节点和左右子树组成，。，其中左右子树同样是一棵二叉树

二叉排序树的性质：

1. 如果左子树不为空，那么左子树上所有结点的值均小于根结点的值
2. 如果右子树不为空，那么右子树上所有结点的值均小于根结点的值
3. 左右子树分别为二叉排序树

重要的是步骤非插入不可，。，。和链表一样，。用个指针。

class TreeNode {
    int data;
    TreeNode left;
    TreeNode right;
    public TreeNode(int data) {
        this.data = data;
        this.left = null;
        this.right = null;
    }
}
class BinaryTree {
    TreeNode root;
    public BinaryTree() {
        root = null;
    }
    public void insert(int data) {
        TreeNode node = new TreeNode(data);
        if (root == null) {
            root = node;
        } else {
            TreeNode dummy = root;
            while (true) {
                if (node.data < dummy.data) {
                    if (dummy.left == null) {
                        dummy.left = node;
                        return;
                    }
                    dummy = dummy.left;
                } else {
                    if (dummy.right == null) {
                        dummy.right = node;
                        return;
                    }
                    dummy = dummy.right;
                }
            }
        }
    }
    public TreeNode create(int[] datas) {
        for (int i = 0; i < datas.length; i++) {
            insert(datas[i]);
        }
        return root;
    }
    public void inOrder(TreeNode root) {
        if (root != null) {
            inOrder(root.left);
            System.out.print(root.data + " ");
            inOrder(root.right);
        }
    }
    public void preOrder(TreeNode root) {
        if (root != null) {
            System.out.print(root.data + " ");
            preOrder(root.left);
            preOrder(root.right);
        }
    }
    public void postOrder(TreeNode root) {
        if (root != null) {
            postOrder(root.left);
            postOrder(root.right);
            System.out.print(root.data + " ");
        }
    }
}
public class Solution {
    public static void main(String[] args) {
        BinaryTree tree = new BinaryTree();
        int[] nums = {1, 3, 4, 5, 6, 4, 3, 2};
        System.out.print("中序：");
        TreeNode root = tree.create(nums);
        tree.inOrder(root);
        System.out.println();
        System.out.print("先序：");
        tree.preOrder(root);
        System.out.println();
        System.out.print("后序：");
        tree.postOrder(root);
        System.out.println();
    }
}