（C#）一个最简单的链表类
一、关于C#链表
C#链表可用类LinkedList来存放。本文中的类MyLinkedList只是实现了该类的最基本的功能。C#中没有指针，但因为C#中类在赋值时传递的是地址，因此仍然可以利用这点制作一个链表。
二、结点类Node和链表类MyLinkedList代码
/// <summary>
/// 链表结点
/// </summary>
class Node
{
//结点数据，前后结点
public object Data;
public Node PreviousNode;
public Node NextNode;
//构造函数
public Node(object data = null)
{
Data = data;
PreviousNode = null;
NextNode = null;
}
//输出结点信息
public override string ToString()
{
return Data.ToString();
}
}
/// <summary>
/// 链表类
/// </summary>
class MyLinkedList
{
//首结点、尾结点
public Node First;
public Node Last;
//下一个结点、上一个结点
public Node NextNode(Node n) { return n.NextNode; }
public Node PreviousNode(Node n) { return n.PreviousNode; }
//结点总数
public int Count;
//构造函数
public MyLinkedList()
{
this.First = null;
this.Last = null;
Count = 0;
}
/// <summary>
/// 在结点node1之后增加结点node2，如果没有该结点则在最后增加
/// </summary>
/// <param name="node1">结点1</param>
/// <param name="node2">结点2</param>
public void AddAfter(Node node1, Node node2)
{
//链表为空的情况
if (First == null)
{
Console.WriteLine("Linked-list is null! Can not find node1(" + node1 + ")");
return;
}
Node temp = First;
do
{
if (temp.Data.Equals(node1.Data))
{
//如果node1是尾结点
if (node1.NextNode == null)
{
node2.NextNode = null;
node2.PreviousNode = node1;
node1.NextNode = node2;
}
else //如果node1不是尾结点
{
node2.NextNode = node1.NextNode;
node2.PreviousNode = node1;
node2.NextNode.PreviousNode = node2;
node1.NextNode = node2; ;
}
Count++;
Console.WriteLine("Node(" + node2 + "): Add Complete!");
return;
}
temp = temp.NextNode;
}
while (temp != null);
Console.WriteLine("Can not find node(" + node1 + "), Misson defeat");
}
/// <summary>
/// 在链表尾部增加结点
/// </summary>
public void AddLast(Node node)
{
//链表为空的情况
if (this.First == null)
{
node.NextNode = null;
node.PreviousNode = null;
this.First = node;
this.Last = node;
}
else //链表不为空的情况
{
Node temp = First;
while(temp.NextNode != null)
{
temp = temp.NextNode;
}
temp.NextNode = node;
node.PreviousNode = temp;
Last = node;
}
Count++;
Console.WriteLine("Node(" + node + "): Add Complete!");
}
/// <summary>
/// 删除指定结点
/// </summary>
/// <param name="node">被删除结点</param>
public void Delete(Node node)
{
if (Count == 0)
{
Console.WriteLine("Can not find node(" + node + ")");
return;
}
Node temp = First;
do
{
//如果数据部分匹配，则删去该结点
if (temp.Data.Equals(node.Data))
{
//temp是尾结点
if (temp.NextNode == null)
{
temp.PreviousNode.NextNode = null;
temp = null;
}
else //temp不是尾结点
{
temp.PreviousNode.NextNode = temp.NextNode;
temp.NextNode.PreviousNode = temp.PreviousNode;
temp = null;
}
Count--;
Console.WriteLine("Node(" + node + "): Delete Complete!");
return;
}
temp = temp.NextNode;
}
while (temp != null);
Console.WriteLine("Can not find node(" + node + "), Misson defeat");
}
/// <summary>
/// 修改结点值
/// </summary>
/// <param name="node">被修改结点</param>
/// <param name="value">结点值</param>
public void Modify(Node node, object value)
{
if (Count == 0)
{
Console.WriteLine("Can not find node(" + node + ")");
return;
}
Node temp = First;
do
{
if (temp.Data.Equals(node.Data))
{
Console.WriteLine("Node: " + temp.Data + " → " + value.ToString());
temp.Data = value;
return;
}
temp = temp.NextNode;
}
while (temp != null);
}
/// <summary>
/// 打印链表
/// </summary>
public void Print()
{
if (First == null)
{
Console.WriteLine("No nodes in this linked-list.");
return;
}
else
{
Console.WriteLine("Print the linked-list...");
Node temp = First;
do
{
Console.WriteLine(temp.ToString());
temp = temp.NextNode;
}
while (temp != null);
Console.WriteLine("Mission Complete!");
}
}
}
三、Main函数的调用示例
static void Main(string[] args)
{
MyLinkedList ll = new MyLinkedList();
//添加三个结点 1 2（在1后） 3（在2后）
Node n1 = new Node("node1");
Node n2 = new Node("node2");
Node n3 = new Node("node3");
ll.AddLast(n1);
ll.AddLast(n2);
ll.AddLast(n3);
//添加三个结点 1.5（在1后） 2.5（在2后） 3.5（在3后）
Node n1dot5 = new Node("node1dot5");
Node n2dot5 = new Node("node2dot5");
Node n3dot5 = new Node("node3dot5");
ll.AddAfter(n1, n1dot5);
ll.AddAfter(n2, n2dot5);
ll.AddAfter(n3, n3dot5);
Console.WriteLine("========================");
//打印链表
ll.Print();
Console.WriteLine("========================");
//删除结点 2 和 3，将结点 2.5 的值改为 "ThisNodeIsModified!"
ll.Delete(n2);
ll.Delete(n3);
ll.Modify(n2dot5, "ThisNodeIsModified!");
Console.WriteLine("========================");
//打印链表
ll.Print();
Console.ReadLine();
}
四、运行结果
