使用数组的java中的BST

public class BST {
    private Node root;

    private class Node {
        private int key;
        private Node left;
        private Node right;

        public Node(int key) {
            this.key = key;
        }
    }

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

    private Node insert(Node node, int key) {
        if (node == null) {
            return new Node(key);
        }

        if (key < node.key) {
            node.left = insert(node.left, key);
        } else if (key > node.key) {
            node.right = insert(node.right, key);
        }

        return node;
    }

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

    private boolean search(Node node, int key) {
        if (node == null) {
            return false;
        }

        if (key == node.key) {
            return true;
        } else if (key < node.key) {
            return search(node.left, key);
        } else {
            return search(node.right, key);
        }
    }

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

    private Node delete(Node node, int key) {
        if (node == null) {
            return null;
        }

        if (key < node.key) {
            node.left = delete(node.left, key);
        } else if (key > node.key) {
            node.right = delete(node.right, key);
        } else {
            if (node.left == null) {
                return node.right;
            } else if (node.right == null) {
                return node.left;
            }

            Node minNode = findMin(node.right);
            node.key = minNode.key;
            node.right = delete(node.right, minNode.key);
        }

        return node;
    }

    private Node findMin(Node node) {
        while (node.left != null) {
            node = node.left;
        }
        return node;
    }
}