C# 二叉树的综合操作（一）：查找、插入、最大（小）值、先序遍历、后序遍历及中序遍历

来源：互联网发布：克里米亚战争知乎编辑：程序博客网时间：2024/05/17 09:19

二叉树是学习数据结构与算法的重要内容，现做综合操作二叉树的汇总。由于关于这方面的文章、书籍已是随处可见，故此间的细节不再赘述，附上一段代码，并提供实例，供参考。代码已测试没有问题。

    public class Node                             // 定义二叉树节点类 Node    {        public int Data;        public Node Left;        public Node Right;        public void Display()        {            Console.WriteLine(Data);        }        public Node(int x)        {            Data = x;        }    }    public class BinaryTree              // 定义二叉树    {        public Node Current;             //         Node Parent;                     // 定义一个 Parent，用于存储当前节点（Current）的父节点，为添加删除节点方法做准备        public Node Root;                // 定义根结点        public BinaryTree()              // 构造函数，初始化二叉树        {            Root = null;        }        public void InOrder(Node theRoot)            // 通过递归，中序遍历        {            if (theRoot != null)            {                InOrder(theRoot.Left);                Console.Write(theRoot.Data + "\t");                InOrder(theRoot.Right);            }        }        public void PreOrder(Node theRoot)          // 通过递归，先序遍历        {            if (theRoot != null)            {                Console.Write(theRoot.Data + "\t");                PreOrder(theRoot.Left);                PreOrder(theRoot.Right);            }        }        public void PostOrder(Node theRoot)        // 通过递归，后序遍历        {            if (theRoot != null)            {                PostOrder(theRoot.Left);                PostOrder(theRoot.Right);                Console.Write(theRoot.Data+"\t");            }        }        public void Insert(int x)                  // 插入节点        {            Node newNode = new Node(x);            Current = Root;            if (Root == null)            {                Root = newNode;            }            else            {                while (true)                {                    Parent = Current;                    if (x < Current.Data)                    {                        Current = Current.Left;                        if (Current == null)                        {                            Parent.Left = newNode;                            break;                        }                    }                    else                    {                        Current = Current.Right;                        if (Current == null)                        {                            Parent.Right = newNode;                            break;                        }                    }                }            }        }        public int Min()              // 查找最小值        {            Current = Root;            while (Current.Left != null)                Current = Current.Left;            return Current.Data;        }        public int Max()              // 查找最大值        {            Current = Root;            while (Current.Right != null)                Current = Current.Right;            return Current.Data;        }        public Node Find(int key)     // 查找某一个确定的节点的值        {            Current = Root;            while (Current != null)            {                if (key == Current.Data)                    break;               // 找到了就结束 while 循环                if (key < Current.Data)                {                    Parent = Current;                    Current = Current.Left;                }                else                {                    Parent = Current;                    Current = Current.Right;                }            }            if (Current == null)                return null;            else                return Current;        }          }    class Program    {        static void Main(string[] args)        {            BinaryTree bst = new BinaryTree();            bst.Insert(25);            bst.Insert(50);            bst.Insert(15);            bst.Insert(33);            bst.Insert(4);            bst.Insert(100);            bst.Insert(20);            bst.Insert(38);            bst.Insert(1);            bst.Insert(10);            bst.Insert(18);            bst.Insert(30);            bst.Insert(32);            Console.WriteLine("The min is: {0}", bst.Min());            Console.WriteLine("The max is: {0}", bst.Max());            Console.Write("Find \"100\": ");            Console.Write(bst.Find(100).Data+"\n");                        Console.WriteLine("\n" + "PreOrder: ");            bst.PreOrder(bst.Root);            Console.WriteLine("\n" +"PostOrder:");            bst.PostOrder(bst.Root);            Console.WriteLine("\n"+"InOrder: ");            bst.InOrder(bst.Root);            Console.Read();        }    }

运行结果：

The min is: 1
The max is: 100
Find "100": 100

PreOrder:
25 15 4 1 10 20 18 50 33 30 32 38 100
PostOrder:
1 10 4 18 20 15 32 30 38 33 100 50 25
InOrder:
1 4 10 15 18 20 25 30 32 33 38 50 100

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