java查找二叉树的代码

以下是Java语言实现查找二叉树的代码：

class Node {
    int value;
    Node left, right;

    Node(int val) {
        value = val;
        left = right = null;
    }
}

public class BinarySearchTree {
    Node root;

    public BinarySearchTree() {
        root = null;
    }

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

    Node insertRec(Node root, int val) {
        if (root == null) {
            root = new Node(val);
            return root;
        }

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

        return root;
    }

    public boolean search(int val) {
        return searchRec(root, val);
    }

    boolean searchRec(Node root, int val) {
        if (root == null)
            return false;

        if (root.value == val)
            return true;

        if (val < root.value)
            return searchRec(root.left, val);

        return searchRec(root.right, val);
    }

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

        tree.insert(50);
        tree.insert(30);
        tree.insert(20);
        tree.insert(40);
        tree.insert(70);
        tree.insert(60);
        tree.insert(80);

        System.out.println(tree.search(70));
        System.out.println(tree.search(90));
    }
}