C#先序遍历2叉树（非递归）

找了下先序遍历二叉树C# 实现貌似没有 顺手些了一个

 大致思路是：

传入根节点，然后依次循环其子节点推入到栈中，

当推入的节点没有子节点的时候（叶子）或者所有子节点均已经遍历过后（上一次遍历的节点是该节点的右子节点），再依次退出栈。

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
 
namespace ConsoleApplication5
{
    class Program
    {
        static void Main(string[] args)
        {
            Node treeRoot = CreateTree();
            scanTree(treeRoot);
        }
 
        private static void scanTree(Node treeRoot)
        {
            List<Node> list = new List<Node>();
            list.Add(treeRoot);
            Node point = treeRoot;
            Write(treeRoot);
            while (true)
            {
                if (!list.Contains(point))
                { //上一轮是移除的操作
                    if (treeRoot.leftSon == point)
                    {//移除的是左结点
                        if (treeRoot.rightSon != null)
                        {
                            treeRoot = treeRoot.rightSon;
                            list.Add(treeRoot);
                            Write(treeRoot);
                            point = treeRoot;
                            continue;
                        }
                        list.Remove(treeRoot);
                        if (list.Count == 0)
                        {
                            break;
                        }
                        point = treeRoot;
                        treeRoot = list[list.Count - 1];
                    }
                    else
                    {//移除的是右结点
                        list.Remove(treeRoot);
                        if (list.Count == 0)
                        {
                            break;
                        }
                        point = treeRoot;
                        treeRoot = list[list.Count - 1];
                    }
                    continue;
                }
 
                if (treeRoot.leftSon != null)
                {
                    treeRoot = treeRoot.leftSon;
                    Write(treeRoot);
                    list.Add(treeRoot);
                    point = treeRoot;
                    continue;
                }
                if (treeRoot.rightSon != null)
                {
                    treeRoot = treeRoot.rightSon;
                    Write(treeRoot);
                    point = treeRoot;
                    list.Add(treeRoot);
                    continue;
                }
                //当前的节点是叶子节点   if (treeRoot.leftSon == null && treeRoot.rightSon == null)
                //{
                    list.Remove(treeRoot);
                    if (list.Count == 0)
                    {
                        break;
                    }
                    point = treeRoot;
                    treeRoot = list[list.Count - 1];
               // }
            }
 
        }
 
        public static void Write(Node node)
        {
            Console.WriteLine(node.Data);
        }
 
        private static Node CreateTree()
        {
            Node a = new Node("A");
           a.leftSon = new Node("B");
            a.rightSon = new Node("C");
           
           a.leftSon.leftSon = new Node("D");
           a.leftSon.rightSon = new Node("E");
           
           a.rightSon.leftSon = new Node("F");
           a.rightSon.rightSon = new Node("G");
 
           a.leftSon.leftSon.leftSon = new Node("H");
           a.leftSon.leftSon.rightSon = new Node("I");
            return a;
        }
    }
 
    class Node
    {
        public string Data { get; set; }
        public Node leftSon { get; set; }
        public Node rightSon { get; set; }
 
        public Node(string data)
        {
            Data = data;
        }
    }
}