需要 Level Order Traversion 帮助，出现错误

Question

我试图弄清楚为什么我从这个 hackerrank.com 问题 (https://www.hackerrank.com/challenges/30-binary-trees/problem) 中得到以下错误：

solution.cs(32,7): error CS1525: Unexpected symbol Node, 期待 class、delegate、enum、interface、partial 或 struct 编译失败：1 个错误，0 个警告

退出状态：255

我已经检查了所有常见的东西，比如分号和大括号被关闭，但我很难过。

我的代码如下，我已经注释了错误开始的地方：

using System;
using System.Collections;
using System.Collections.Generic;
using System.IO;
using System.Linq;
class Node{
    public Node left,right;
    public int data;
    public Node(int data){
        this.data=data;
        left=right=null;
    }
}
class Solution{
    static Queue<Node> nodeQueue = new Queue<Node>();
    static void levelOrder(Node root){
        //Write your code here
        nodeQueue.Enqueue(root);
        while (nodeQueue.Count > 0){
            var n = nodeQueue.Dequeue();
            Console.Write(n.data + " ");
            if (n.left != null) {
                nodeQueue.Enqeue(n.left);
            }
            if (n.right != null) {
                nodeQueue.Enqueue(n.right);
            }
        }
    }   
}
// Right here is where it is saying it's not expecting "NODE", the line below
    static Node insert(Node root, int data){
        if(root==null){
            return new Node(data);
        }
        else{
            Node cur;
            if(data<=root.data){
                cur=insert(root.left,data);
                root.left=cur;
            }
            else{
                cur=insert(root.right,data);
                root.right=cur;
            }
            return root;
        }
    }
    static void Main(String[] args){
        Node root=null;
        int T=Int32.Parse(Console.ReadLine());
        while(T-->0){
            int data=Int32.Parse(Console.ReadLine());
            root=insert(root,data);            
        }
        levelOrder(root);

    }
}

Answer 1

我将您的代码复制到了默认的控制台应用程序中，它对我来说构建时没有错误。

using System;

namespace ConsoleApp2
{
    using System;
    using System.Collections;
    using System.Collections.Generic;
    using System.IO;
    using System.Linq;
    class Node
    {
        public Node left, right;
        public int data;
        public Node(int data)
        {
            this.data = data;
            left = right = null;
        }
    }
    class Solution
    {
        static Queue<Node> nodeQueue = new Queue<Node>();
        static void levelOrder(Node root)
        {
            //Write your code here
            nodeQueue.Enqueue(root);
            while (nodeQueue.Count > 0)
            {
                var n = nodeQueue.Dequeue();
                Console.Write(n.data + " ");
                if (n.left != null)
                {
                    nodeQueue.Enqueue(n.left);
                }
                if (n.right != null)
                {
                    nodeQueue.Enqueue(n.right);
                }
            }
        }

    // Right here is where it is saying it's not expecting "NODE", the line below
        static Node insert(Node root, int data)
        {
            if (root == null)
            {
                return new Node(data);
            }
            else
            {
                Node cur;
                if (data <= root.data)
                {
                    cur = insert(root.left, data);
                    root.left = cur;
                }
                else
                {
                    cur = insert(root.right, data);
                    root.right = cur;
                }
                return root;
            }
        }
        static void Main(String[] args)
        {
            Node root = null;
            int T = Int32.Parse(Console.ReadLine());
            while (T-- > 0)
            {
                int data = Int32.Parse(Console.ReadLine());
                root = insert(root, data);
            }
            levelOrder(root);

        }
    }
}