如何在C#中将树的所有叶子添加到列表中

using System;
using System.Collections.Generic;

public class TreeNode
{
    public int Value { get; set; }
    public List<TreeNode> Children { get; set; }

    public TreeNode(int value)
    {
        Value = value;
        Children = new List<TreeNode>();
    }
}

public class TreeLeafCollector
{
    public List<int> CollectLeaves(TreeNode root)
    {
        List<int> leaves = new List<int>();
        CollectLeavesHelper(root, leaves);
        return leaves;
    }

    private void CollectLeavesHelper(TreeNode node, List<int> leaves)
    {
        if (node.Children.Count == 0)
        {
            leaves.Add(node.Value);
        }
        else
        {
            foreach (var child in node.Children)
            {
                CollectLeavesHelper(child, leaves);
            }
        }
    }
}

public class Program
{
    public static void Main(string[] args)
    {
        // 构建一个树的示例
        TreeNode root = new TreeNode(1);
        TreeNode node2 = new TreeNode(2);
        TreeNode node3 = new TreeNode(3);
        TreeNode node4 = new TreeNode(4);
        TreeNode node5 = new TreeNode(5);
        TreeNode node6 = new TreeNode(6);

        root.Children.Add(node2);
        root.Children.Add(node3);
        node2.Children.Add(node4);
        node2.Children.Add(node5);
        node3.Children.Add(node6);

        // 收集树的叶子节点
        TreeLeafCollector collector = new TreeLeafCollector();
        List<int> leaves = collector.CollectLeaves(root);

        // 打印叶子节点
        foreach (var leaf in leaves)
        {
            Console.WriteLine(leaf);
        }
    }
}