A complete example of C realizing single linked list of linear table
- 2021-10-24 23:34:56
- OfStack
In this paper, the method of realizing single linked list (linear list) by C # is described as an example. Share it for your reference, as follows:
Sequential tables consist of contiguous memory, but linked lists are different. The advantage of sequential table lies in finding, and the advantage of linked list lies in inserting elements and other operations. Example of sequence table: https://www.ofstack.com/article/87605. htm
It should be noted that the Add () method of a single linked list should not be called frequently, especially when the linked list is long, because every Add will traverse from the head node to the tail node. The optimization method of this disadvantage is to add nodes to the head, but the order is reversed.
Therefore, in the following example, when executing Purge (cleaning repeating elements), instead of using the Add () method to add elements, a node is defined so that it always points to the last node of the target single linked list, so that it does not have to traverse from beginning to end every time.
In addition, the linked list can also be made into a circular linked list, that is, the next attribute of the last node is equal to head, and the main operation is similar to that of a single linked list. It is judged that the last node is not equal to null, but equal to head
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
namespace LinearList
{
//定义线性表的行为，可供顺序表类和单链表类继承
public interface IListDS<T>
{
int GetLength();
void Insert(T item, int i);
void Add(T item);
bool IsEmpty();
T GetElement(int i);
void Delete(int i);
void Clear();
int LocateElement(T item);
void Reverse();
}
//链表节点类
class Node<T>
{
private T tData;
private Node<T> nNext;
public T Data
{
get { return this.tData; }
set { this.tData = value; }
}
public Node<T> Next
{
get { return this.nNext; }
set { this.nNext = value; }
}
public Node()
{
this.tData = default(T);
this.nNext = null;
}
public Node(T t)
{
this.tData = t;
this.nNext = null;
}
public Node(T t,Node<T> node)
{
this.tData = t;
this.nNext = node;
}
}
//该枚举表示单链表Add元素的位置，分头部和尾部两种
enum AddPosition {Head,Tail};
//单链表类
class LinkedList<T>:IListDS<T>
{
private Node<T> tHead;//单链表的表头
public Node<T> Head
{
get { return this.tHead; }
set { this.tHead = value; }
}
public LinkedList()
{
this.tHead = null;
}
public LinkedList(Node<T> node)
{
this.tHead = node;
}
public void Add(T item,AddPosition p)//选择添加位置
{
if (p == AddPosition.Tail)
{
this.Add(item);//默认添加在末尾
}
else//从头部添加会节省查找的开销，时间复杂度为O(1)不必每次都循环到尾部，这恰好是顺序表的优点
{
Node<T> node = this.Head;
Node<T> nodeTmp = new Node<T>(item);
if (node == null)
{
this.Head = nodeTmp;
}
else
{
nodeTmp.Next = node;
this.tHead = nodeTmp;
}
}
}
#region IListDS<T> 成员
public int GetLength()
{
Node<T> node = new Node<T>();
int count = 0;
node = this.tHead;
while (node != null)
{
count++;
node = node.Next;
}
return count;
}
public void Insert(T item, int i)//i最小从1开始
{
Node<T> insertNode = new Node<T>(item, null);//实例化待添加的Node
if (this.tHead == null && i == 1)
{
this.tHead = insertNode;
return;
}
if (i < 1 || i > this.GetLength() || (this.tHead == null && i != 1))
{
Console.WriteLine("There are no elements in this linked list!");
return;
}
int j = 1;
Node<T> node = this.tHead;
Node<T> nodeTmp;
while (node != null && j < i)//循环结束时，保证node为第i个node
{
node = node.Next;
j++;
}
nodeTmp = node.Next;//原来的单链表的第i+1个node
node.Next = insertNode;//第i个node后的node修改为待插入的node
insertNode.Next = nodeTmp;//待插入的node插入后，其后继node为原来链表的第i+1个node
}
public void Add(T item)//添加至尾部，时间复杂度为O(n)，如果添加至头部，则会节省循环的开销
{
Node<T> LastNode = new Node<T>(item, null);//实例化待添加的Node
if (this.tHead == null)
{
this.tHead = LastNode;
}
else
{
Node<T> node = this.tHead;
while (node.Next != null)
{
node = node.Next;
}
node.Next = LastNode;
}
}
public bool IsEmpty()
{
return this.tHead == null;
}
public T GetElement(int i)//设i最小从1开始
{
if (i < 1 || i > this.GetLength())
{
Console.WriteLine("The location is not right!");
return default(T);
}
else
{
if (i == 1)
{
return this.tHead.Data;
}
else
{
Node<T> node = this.tHead;
int j = 1;
while (j < i)
{
node = node.Next;
j++;
}
return node.Data;
}
}
}
public void Delete(int i)//设i最小从1开始
{
if (i < 1 || i > this.GetLength())
{
Console.WriteLine("The location is not right!");
}
else
{
if (i == 1)
{
Node<T> node = this.tHead;
this.tHead = node.Next;
}
else
{
Node<T> node = this.tHead;
int j = 1;
while (j < i-1)
{
node = node.Next;
j++;
}
node.Next = node.Next.Next;
}
}
}
public void Clear()
{
this.tHead = null;//讲thead设为null后，则所有后继结点由于失去引用，等待GC自动回收
}
public int LocateElement(T item)//返回值最小从1开始
{
if (this.tHead == null)
{
Console.WriteLine("There are no elements in this linked list!");
return -1;
}
Node<T> node = this.tHead;
int i = 0;
while (node != null)
{
i++;
if (node.Data.Equals(item))//如果Data是自定义类型，则其Equals函数必须override
{
return i;
}
node = node.Next;
}
Console.WriteLine("No found!");
return -1;
}
public void Reverse()
{
if (this.tHead == null)
{
Console.WriteLine("There are no elements in this linked list!");
}
else
{
Node<T> node = this.tHead;
if (node.Next == null)//如果只有头节点，则不作任何改动
{
}
else
{
Node<T> node1 = node.Next;
Node<T> node2;
while (node1 != null)
{
node2 = node.Next.Next;
node.Next = node2;//可以发现node始终未变，始终是原来的那个头节点
node1.Next = this.tHead;
this.tHead = node1;
node1 = node2;
}
}
}
}
#endregion
}
class Program
{
static void Main(string[] args)
{
/*测试单链表的清空
lList.Clear();
Node<int> n = new Node<int>();
n = lList.Head;
while (n != null)
{
Console.WriteLine(n.Data);
n = n.Next;
}
Console.ReadLine();
*/
/*测试单链表返回元素个数
LinkedList<int> lList = new LinkedList<int>();
lList.Add(3);
Console.WriteLine(lList.GetLength());
Console.ReadLine();
*/
/*测试单链表插入
LinkedList<int> lList = new LinkedList<int>();
lList.Insert(0,1);
lList.Add(1);
lList.Add(2);
lList.Add(3);
lList.Add(4);
lList.Insert(99,3);
Node<int> n = new Node<int>();
n = lList.Head;
while (n != null)
{
Console.WriteLine(n.Data);
n = n.Next;
}
Console.ReadLine();
*/
/*测试单链表获取某位置的值
LinkedList<int> lList = new LinkedList<int>();
lList.Add(1);
lList.Add(2);
lList.Add(3);
lList.Add(4);
Console.WriteLine(lList.GetElement(1));
Console.ReadLine();
*/
/*测试单链表删除某位置的值
LinkedList<int> lList = new LinkedList<int>();
lList.Add(1);
lList.Add(2);
lList.Add(3);
lList.Add(4);
Node<int> n = new Node<int>();
n = lList.Head;
while (n != null)
{
Console.WriteLine(n.Data);
n = n.Next;
}
Console.ReadLine();
lList.Delete(2);
Node<int> m = new Node<int>();
m = lList.Head;
while (m != null)
{
Console.WriteLine(m.Data);
m = m.Next;
}
Console.ReadLine();
*/
/*测试单链表按值查找元素位置
LinkedList<int> lList = new LinkedList<int>();
lList.Add(1);
lList.Add(2);
lList.Add(3);
lList.Add(4);
Console.WriteLine(lList.LocateElement(3));
Console.ReadLine();
*/
/*测试单链表Reverse操作（逆序）
LinkedList<int> lList = new LinkedList<int>();
lList.Add(1);
lList.Add(2);
lList.Add(3);
lList.Add(4);
lList.Add(5);
Node<int> m = new Node<int>();
m = lList.Head;
while (m != null)
{
Console.WriteLine(m.Data);
m = m.Next;
}
Console.ReadLine();
lList.Reverse();
Node<int> n = new Node<int>();
n = lList.Head;
while (n != null)
{
Console.WriteLine(n.Data);
n = n.Next;
}
Console.ReadLine();
*/
/*测试单链表从头部添加元素
LinkedList<int> lList = new LinkedList<int>();
lList.Add(1,AddPosition.Head);
lList.Add(2, AddPosition.Head);
lList.Add(3, AddPosition.Head);
lList.Add(4, AddPosition.Head);
lList.Add(5, AddPosition.Head);
Node<int> m = new Node<int>();
m = lList.Head;
while (m != null)
{
Console.WriteLine(m.Data);
m = m.Next;
}
Console.ReadLine();
*/
/*测试对单链表清除重复元素操作（返回另1链表）。这个例子中避免使用Add（）方法，因为每个Add（）都要从头到尾进行遍历，不适用Add（）方法
就要求对目标链表的最后1个元素实时保存。另1种避免的方法在于从头部Add，但这样的最终结果为倒序
LinkedList<int> lList = new LinkedList<int>();//原链表
LinkedList<int> lList2 = new LinkedList<int>();//保存结果的链表
lList.Add(1);
lList.Add(2);
lList.Add(1);
lList.Add(3);
lList.Add(3);
lList.Add(4);
lList.Add(5);
Node<int> m = new Node<int>();
m = lList.Head;
while (m != null)
{
Console.WriteLine(m.Data);
m = m.Next;
}
Console.ReadLine();
Node<int> node1 = lList.Head;//标识原链表的当前要参与比较大小的元素，即可能放入链表2中的元素
Node<int> node2;//标识结果单链表的最后1个元素，避免使用Add函数造成多次遍历
Node<int> node3;//对node1的后继进行暂时保存，并最终付给node1
node3 = node1.Next;
lList2.Head = node1;//链表1的头结点肯定要加入链表2
node2 = lList2.Head;//node2表示链表2的最后1个元素，此时最后1个元素为头结点
node2.Next = null;//由于是把node1赋给了链表2的头结点，必须把它的后续结点设为null，否则会1起带过来
node1 = node3;//如果没有node3暂存node1的后继，对lList2.Head后继赋为null的就会同时修改node1的后继，因为两者指向同1块内存
while (node1 != null)
{
//在iList2中比较大小
Node<int> tmp = lList2.Head;
if (node1.Data.Equals(tmp.Data))
{
node1 = node1.Next;
continue;//若相等，则node1向后移1位，重新计算
}
else
{
Node<int> tmp2 = tmp;
tmp = tmp.Next;//tmp标识链表2的用于循环的节点，与node比较
if (tmp == null)//当链表2中现有元素与node1都不相等时
{
node3 = node1.Next;
node2.Next = node1;
node2 = node1;
node2.Next = null;
node1 = node3;
continue;
}
while (tmp != null)//tmp不为null时，1直循环到它为null
{
if (node1.Data.Equals(tmp.Data))
{
node1 = node1.Next;
}
else
{
tmp2 = tmp;
tmp = tmp.Next;
if (tmp == null)
{
node3 = node1.Next;
node2.Next = node1;
node2 = node1;
node2.Next = null;
node1 = node3;
}
}
}
}
}
//输出清除重复处理后的数组
Node<int> n = new Node<int>();
n = lList2.Head;
while (n!= null)
{
Console.WriteLine(n.Data);
n = n.Next;
}
Console.ReadLine();
*/
}
}
}
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