数据结构学习（1）：搜索二叉树

using System;
using System.IO;

namespace BinaryTreeSearch
{
    /**//// <summary>
    /// Class1 的摘要说明。
    /// </summary>
    class BinaryTreeSearch
    {
        /**//// <summary>
        /// 应用程序的主入口点。
        /// </summary>
        [STAThread]
        static void Main(string[] args)
        {
            //
            // TODO: 在此处添加代码以启动应用程序
            //
        }
        public void init()
        {
            //构造一个空的二叉搜索树开始
            BinarySearchTree T=new BinarySearchTree();//T初始为空

        }
    }
    class BinarySearchTree
    {
        //BinarySearchTree中有一个存储指向二叉搜索树根结点指针（或存有证明为空树
        //的null)的私有数据域
        private TreeNode rootNode;
        //BinarySearchTree的各种方法
        //Insert方法所用的辅助方法
        private TreeNode insertKey(TreeNode T,ComparisonKey K)
        {
            if(T==null)
            {
                TreeNode N=new TreeNode();//构建一个新的TreeNode
                N.key=K;
                return N;
            }
            else
            {
                if(K.compareTo(T.key)<0)
                {
                    T.llink=insertKey(T.llink,K);
                    return T;
                }
                else
                {
                    T.rlink=insertKey(T.rlink,K);
                    return T;
                }
            }
        }//end insertKey


        void insert(string K)
        {
            rootNode=insertKey(rootNode,new StringKey(K));
        }//end insert

        TreeNode find(ComparisonKey K)
        {
            TreeNode T=rootNode;
            int result;

            while(T!=null)
            {
                if((result=K.compareTo(T.key))<0)
                {
                    T=T.llink;
                }
                else if(result==0)
                {
                    return T;
                }
                else
                {
                    T=T.rlink;
                }//end if
            }
            return T;//如果搜索失败 返回null
        }

        TreeNode find(String K)
        {
            return find(new StringKey(K));
        }
    }
    class TreeNode
    {
        ComparisonKey key;
        TreeNode llink;
        TreeNode rlink;
    }
    public interface ComparisonKey
    {
        //        如果K1和K2均为ComparisonKey，那么K1.compareTo(k2)就会有三个值0,1,-1,
        //        就是K1==K2,K1>K2,K1<K2顺序是compareTo方法定义的优先级别顺序
        int compareTo(ComparisonKey value);
        //将ComparisonKey转换成可以打印的字符串
        string toOurString();
    }

    public class PQItem:ComparisonKey
    {

        private int key;//key数据包括给出元素优先级别的整数关键字
        public PQItem(int value)
        {
            key=value;
        }
        ComparisonKey 成员#region ComparisonKey 成员

        public int compareTo(ComparisonKey value)
        {
            int a=this.key;
            int b=((PQItem)value).key;
            return ((a==b)?0:((a>b)?1:-1));
        }

        public string toOurString()
        {
            return this.key.ToString();
        }

        #endregion

    }

}