C#实现二叉树，外带中序遍历

1. using System;
3. namespace BinaryTree
4. {
5.     // Binary Tree的结点类
6.     class Node
7.     {
8.         public int Data { get; set; }
9.         public Node LeftSubNode { get; set; }
10.         public Node RightSubNode { get; set; }
12.         // 结点为自己追加子结点（与向左/向右追加结合，形成递归）
13.         public void Append(Node subNode)
14.         {
15.             if (subNode.Data <= this.Data)
16.             {
17.                 this.AppendLeft(subNode);
18.             }
19.             else
20.             {
21.                 this.AppendRight(subNode);
22.             }
23.         }
25.         // 向左追加
26.         public void AppendLeft(Node subNode)
27.         {
28.             if (this.LeftSubNode == null)
29.             {
30.                 this.LeftSubNode = subNode;
31.             }
32.             else
33.             {
34.                 this.LeftSubNode.Append(subNode);
35.             }
36.         }
38.         // 向右追加
39.         public void AppendRight(Node subNode)
40.         {
41.             if (this.RightSubNode == null)
42.             {
43.                 this.RightSubNode = subNode;
44.             }
45.             else
46.             {
47.                 this.RightSubNode.Append(subNode);
48.             }
49.         }
51.         // 结点显示自己的数据
52.         public void ShowData()
53.         {
54.             Console.WriteLine("Data={0}", this.Data);
55.         }
56.     }
58.     // Binary Tree类
59.     class Tree
60.     {
61.         // 根结点
62.         public Node Root { get; set; }
64.         // 以某结点为起点，插入结点
65.         public void Insert(Node newNode)
66.         {
67.             if (this.Root == null)
68.             {
69.                 this.Root = newNode;
70.             }
71.             else
72.             {
73.                 this.Root.Append(newNode);
74.             }
75.         }
77.         // 重载，默认以根结点为起点插入
78.         public void MidTravel()
79.         {
80.             this.MidTravel(this.Root);
81.         }
82.         
83.         // 中序遍历（递归）
84.         public void MidTravel(Node node)
85.         {
86.             if (node.LeftSubNode != null)
87.             {
88.                 this.MidTravel(node.LeftSubNode);
89.             }
91.             node.ShowData();
93.             if (node.RightSubNode != null)
94.             {
95.                 this.MidTravel(node.RightSubNode);
96.             }
97.         }
98.     }
100.     class Program
101.     {
102.         static void Main(string[] args)
103.         {
104.             Tree tree = new Tree();
105.             
106.             tree.Insert(new Node { Data = 3 });
107.             tree.Insert(new Node { Data = 6 });
108.             tree.Insert(new Node { Data = 2 });
109.             tree.Insert(new Node { Data = 7 });
110.             tree.Insert(new Node { Data = 18 });
111.             
112.             tree.MidTravel();
114.         }
115.     }
116. }