C#实现单链表

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace SingleList
{
    class Program
    {
        static void Main(string[] args)
        {
            MyLinkList<string> myLinkList = new MyLinkList<string>();//实例化一个链表
            Console.WriteLine(myLinkList.GetLength());//获取长度

            //添加元素
            myLinkList.Append("hello");
            myLinkList.Append("C#");
            myLinkList.Append("I");
            myLinkList.Append("love");
            myLinkList.Append("U");

            //myLinkList.Insert("!", 6);//在i结点前插入元素，位置错误测试
            //myLinkList.InsertPost("!", 5);//在i结点后插入元素，位置错误测试

            //myLinkList.InsertPost("，", 1);  //后插元素  
            //myLinkList.Insert("，", 4);  //前插元素  
            
            //Console.WriteLine(myLinkList.GetElement(4));//获取结点,并显示  

            myLinkList.Delete(1);  //删除结点  

            myLinkList.Display();

            Console.WriteLine(myLinkList.GetLength()); //显示链表长度  
            Console.Read();

        }
    }

    //单链表节点类，采用泛型
    public class Node<T>
    {
        private T data;//数据域，当前节点的数据
        private Node<T> next;//引用域，即下一节点

        //构造器，数据域+引用域，普通节点
        public Node(T item, Node<T> p)
        {
            data = item;
            next = p;
        }

        //构造器：引用域，头节点
        public Node(Node<T> p)
        {
            next = p;
        }

        //构造器，数据域，尾节点
        public Node(T val)
        {
            data = val;
            next = null;
        }

        //构造器：无参数
        public Node()
        {
            data = default(T);
            next = null;
        }

        //数据域属性
        public T Data
        {
            get { return data; }
            set { data = value; }
        }

        //引用域属性
        public Node<T> Next
        {
            get { return next; }
            set { next = value; }
        }
    }

    //链表类，包含链表定义以及基本的操作方法
    public class MyLinkList<T>
    {
        private Node<T> head;//单链表的头节点

        //头节点属性
        public Node<T> Head
        {
            get { return head; }
            set { head = value; }
        }

        //构造器
        public MyLinkList()
        {
            head = null;
        }

        //求单链表的长度
        public int GetLength()
        {
            Node<T> p = head;
            int len = 0;
            while (p != null)
            {
                ++len;
                p = p.Next;
            }
            return len;
        }

        //清空单链表
        public void Clear()
        {
            head = null;
        }

        //判断单链表是否为空
        public bool IsEmpty()
        {
            if (head == null)
                return true;
            else
                return false;
        }

        //在单链表的末尾添加新的元素
        public void Append(T item)
        {
            Node<T> q = new Node<T>(item);
            Node<T> p = new Node<T>();
            if (head == null)
            {
                head = q;
                return;
            }
            p = head;
            while (p.Next != null)
            {
                p = p.Next;
            }
            p.Next = q;
        }

        //在单链表的第i个节点的位置前插入一个值为item的结点
        public void Insert(T item, int i)
        {
            if (IsEmpty() || i < 1 || i > GetLength())
            {
                Console.WriteLine("LinkList is empty or Position is error!");
                return;
            }
            if (i == 1)
            {
                Node<T> q = new Node<T>(item);
                q.Next = head;
                head = q;
                return;
            }
            Node<T> p = head;
            Node<T> r = new Node<T>();
            int j = 1;
            while (p.Next != null && j < i)
            {
                r = p;
                p = p.Next;
                ++j;
            }
            if (j == i)
            {
                Node<T> q = new Node<T>(item);
                q.Next = p;
                r.Next = q;
            }
            else
            {
                Console.WriteLine("The" + i + "th node is not exist!");
            }
        }

        //在单链表的第i个节点的位置后插入一个值为item的结点
        public void InsertPost(T item, int i)
        {
            if (IsEmpty() || i < 1 || i > GetLength())
            {
                Console.WriteLine("LinkList is empty or Position is error!");
                return;
            }
            if (i == 1)
            {
                Node<T> q = new Node<T>(item);
                q.Next = head.Next;
                head.Next = q;
                return;
            }
            Node<T> p = head;
            int j = 1;
            while (p != null && j < i)
            {
                p = p.Next;
                ++j;
            }
            if (j == i)
            {
                Node<T> q = new Node<T>(item);
                q.Next = p.Next;
                p.Next = q;
            }
            else
            {
                Console.WriteLine("The" + i + "th node is not exist!");
            }
        }

        //删除单链表的第i个节点
        public T Delete(int i)
        {
            if (IsEmpty() || i < 0 || i > GetLength())
            {
                Console.WriteLine("Linklist is empty or Position is error!");
                return default(T);
            }
            Node<T> q = new Node<T>();
            if (i == 1)
            {
                q = head;
                head = head.Next;
                return q.Data;
            }
            Node<T> p = head;
            int j = 1;
            while (p.Next != null && j < i)
            {
                ++j;
                q = p;
                p = p.Next;
            }
            if (j == i)
            {
                q.Next = p.Next;
                return p.Data;
            }
            else
            {
                Console.WriteLine("The" + i + "th node is not exist!");
                return default(T);
            }
        }

        //获得单链表的第i个数据元素
        public T GetElement(int i)
        {
            if (IsEmpty() || i < 0 || i > GetLength())
            {
                Console.WriteLine("Linklist is empty or Position is error!");
                return default(T);
            }
            Node<T> p = new Node<T>();
            p = head;
            int j = 1;
            while (p.Next != null && j < i)
            {
                ++j;
                p = p.Next;
            }
            if (j == i)
            {
                return p.Data;
            }
            else
            {
                Console.WriteLine("The" + i + "th node is not exist!");
                return default(T);
            }
        }

        //在链表中查找值为value的结点
        public int Locate(int value)
        {
            if (IsEmpty())
            {
                Console.WriteLine("Linklist is empty!");
                return -1;
            }
            Node<T> p = new Node<T>();
            p = head;
            int i = 1;
            while (!p.Data.Equals(value) && p.Next != null)
            {
                p = p.Next;
                ++i;
            }
            return i;
        }

        //显示链表
        public void Display()
        {
            Node<T> p = new Node<T>();
            p = head;
            while (p != null)
            {
                Console.WriteLine(p.Data + " ");
                p = p.Next;
            }
        }
    }
}