使用c#将平面对象转换为层次结构

using System;
using System.Collections.Generic;

public class Node
{
    public int Id { get; set; }
    public string Name { get; set; }
    public List<Node> Children { get; set; }
    
    public Node(int id, string name)
    {
        Id = id;
        Name = name;
        Children = new List<Node>();
    }
}

public class ConvertToHierarchy
{
    public static Node Convert(List<Node> nodes)
    {
        Node root = null;
        Dictionary<int, Node> nodeMap = new Dictionary<int, Node>();

        foreach (var node in nodes)
        {
            if (nodeMap.ContainsKey(node.Id))
            {
                throw new Exception("Duplicate node ID found!");
            }
            nodeMap[node.Id] = node;
        }

        foreach (var node in nodes)
        {
            if (node.Id == 0)
            {
                root = node;
            }
            else if (nodeMap.ContainsKey(node.Id))
            {
                nodeMap[node.Id].Children.Add(node);
            }
        }

        return root;
    }
}

public class Program
{
    public static void Main(string[] args)
    {
        List<Node> nodes = new List<Node>
        {
            new Node(0, "Root"),
            new Node(1, "Node 1"),
            new Node(2, "Node 2"),
            new Node(3, "Node 3"),
            new Node(4, "Node 4"),
            new Node(5, "Node 5"),
        };

        nodes[1].Children.Add(nodes[3]);
        nodes[1].Children.Add(nodes[4]);
        nodes[2].Children.Add(nodes[5]);

        Node root = ConvertToHierarchy.Convert(nodes);

        // 打印层次结构
        PrintHierarchy(root);
    }

    public static void PrintHierarchy(Node node, int level = 0)
    {
        Console.WriteLine(new string('-', level) + node.Name);

        foreach (var child in node.Children)
        {
            PrintHierarchy(child, level + 1);
        }
    }
}