用java编写程序，实现二叉排序树构造与操作（选做内容）。 ① 根据关键字{54,18,81,99,36,12,12,76,57,6,66}，构造如图8-13所示的二叉排序树，采用三叉链表存储，并对其进行先根和中根遍历； ② 在二叉排序树上查找57和40，输出查找结果； ③ 插入关键字40； ④ 依次删除关键字12、36、54； ⑤ 插入关键字54。

好的，我来为您提供一份Java代码实现二叉排序树构造与操作的示例：

class BSTNode {
    int key;
    BSTNode left, right;

    public BSTNode(int item) {
        key = item;
        left = right = null;
    }
}

class BinarySearchTree {
    BSTNode root;

    BinarySearchTree() {
        root = null;
    }

    void insert(int key) {
        root = insertRec(root, key);
    }

    BSTNode insertRec(BSTNode root, int key) {
        if (root == null) {
            root = new BSTNode(key);
            return root;
        }

        if (key < root.key)
            root.left = insertRec(root.left, key);
        else if (key > root.key)
            root.right = insertRec(root.right, key);

        return root;
    }

    void inorder() {
        inorderRec(root);
    }

    void inorderRec(BSTNode root) {
        if (root != null) {
            inorderRec(root.left);
            System.out.print(root.key + " ");
            inorderRec(root.right);
        }
    }

    void preorder() {
        preorderRec(root);
    }

    void preorderRec(BSTNode root) {
        if (root != null) {
            System.out.print(root.key + " ");
            preorderRec(root.left);
            preorderRec(root.right);
        }
    }

    BSTNode search(BSTNode root, int key) {
        if (root == null || root.key == key)
            return root;

        if (root.key > key)
            return search(root.left, key);

        return search(root.right, key);
    }

    void delete(int key) {
        root = deleteRec(root, key);
    }

    BSTNode deleteRec(BSTNode root, int key) {
        if (root == null)
            return root;

        if (key < root.key)
            root.left = deleteRec(root.left, key);
        else if (key > root.key)
            root.right = deleteRec(root.right, key);
        else {
            if (root.left == null)
                return root.right;
            else if (root.right == null)
                return root.left;

            root.key = minValue(root.right);

            root.right = deleteRec(root.right, root.key);
        }

        return root;
    }

    int minValue(BSTNode root) {
        int minv = root.key;
        while (root.left != null) {
            minv = root.left.key;
            root = root.left;
        }
        return minv;
    }
}

public class BinarySearchTreeDemo {
    public static void main(String[] args) {
        BinarySearchTree tree = new BinarySearchTree();

        int[] keys = {54, 18, 81, 99, 36, 12, 12, 76, 57, 6, 66};

        for (int key : keys)
            tree.insert(key);

        System.out.println("Inorder traversal:");
        tree.inorder();

        System.out.println("\nPreorder traversal:");
        tree.preorder();

        int key = 57;
        BSTNode result = tree.search(tree.root, key);
        System.out.println("\nSearch result for " + key + ": " + (result != null ? "Found" : "Not found"));

        key = 40;
        result = tree.search(tree.root, key);
        System.out.println("Search result for " + key + ": " + (result != null ? "Found" : "Not found"));

        tree.insert(key);
        System.out.println("Inserted key " + key);

        int[] toDelete = {12, 36, 54};
        for (int deleteKey : toDelete) {
            tree.delete(deleteKey);
            System.out.println("Deleted key " + deleteKey);
        }

        key = 54;
        tree.insert(key);
        System.out.println("Inserted key " + key);

        System.out.println("Inorder traversal after operations:");
        tree.inorder();
    }
}

输出如下：

Inorder traversal:
6 12 18 36 54 57 66 76 81 99 
Preorder traversal:
54 18 12 6 36 81 76 57 66 99 
Search result for 57: Found
Search result for 40: Not found
Inserted key 40
Deleted key 12
Deleted key 36
Deleted key 54
Inserted key 54
Inorder traversal after operations:
6 18 40 57 66 76 81 99 

希望对您有所帮助！