按照自己的想法和思路写了一下带头结点的单链表,并进行了测试,毕竟自己能力有限,可能有的地方没有测试到,还可能存在一些潜在的错误。
    头文件:
   
#include <iostream>
using namespace std;

typedef struct Node
{//结点结构
  int value;
  struct Node * next;
}Node,*Link;

typedef struct List
{
  Link head,tail;
  int length;
}List,*LinkList;

LinkList NewList(void)
{//新建一个空链表
  LinkList list;
  list=new List;//为链表指针分配空间
  list->head=new Node;//为头结点分配空间
  if(!list->head)//分配失败
    cout<<"Failed."<<endl;
  list->tail=list->head;
  list->tail->next=NULL;
  list->length=0;
  return list;
}

int ListLength(List list)
{
  return list.length;
}

bool IsEmptyList(List list)
{
  if(list.length==0)
    return true;
  return false;
}

void InsertElemToHead(LinkList list,int elem)
{
  Link p;
  p=new Node;
  p->value=elem;
  if(IsEmptyList(*list))
  {
    list->head->next=p;
    list->tail=p;
    p->next=NULL;
  }
  else
  {
    p->next=list->head->next;
    list->head->next=p;
  }
  ++list->length;
}

void InsertElemToEnd(LinkList list,int elem)
{
  Link p;
  p=new Node;
  p->value=elem;
  p->next=NULL;//
  if(IsEmptyList(*list))
  {
    list->head->next=p;
    list->tail=p;
  }
  else
  {
    list->tail->next=p;
    list->tail=p;//改变表尾指针
  }
  ++list->length;
}

void InsertElemToList(LinkList list,int pos,int elem)
{
  if(pos<1 || pos>ListLength(*list)+1)
    cout<<"The position is invalidate."<<endl;
  else
  {
    if(pos==1)
    {
      InsertElemToHead(list,elem);
    }
    else if(pos==ListLength(*list)+1)
    {
      InsertElemToEnd(list,elem);
    }
    else
    {
      Link p,q;
      p=new Node;
      p->value=elem;
      q=list->head->next;//q指向第一个结点
      for(int i=1;i<pos-1;++i)
      {//找到第pos-1个结点
        q=q->next;
      }
      p->next=q->next;
      q->next=p;
      ++list->length;
    }
  }
}

void DeleteElemFromHead(LinkList list,int &elem)
{
  Link p=list->head->next;
  if(IsEmptyList(*list))
  {//表空
    cout<<"The list is empty,you can't delete element."<<endl;
  }
  else
  {//表非空
    if(ListLength(*list)==1)
    {//表长为1
      list->head->next=NULL;
      list->tail=list->head;
      elem=p->value;
      free(p);
    }
    else
    {
      list->head->next=p->next;
      elem=p->value;
      free(p);
    }
    --list->length;
  }
}

void DeleteElemFromEnd(LinkList list,int &elem)
{
  Link p=list->head->next;
  Link q;
  if(IsEmptyList(*list))
  {
    cout<<"The list is empty,you can't delete element."<<endl;
  }
  else
  {
    if(ListLength(*list)==1)
    {
      list->head->next=NULL;
      list->tail=list->head;
      elem=p->value;
      free(p);
    }
    else
    {
      q=list->tail;
      while(p->next!=q)
        p=p->next;//找到表尾的前一个结点
      list->tail=p;
      p->next=NULL;
      elem=q->value;
      free(q);
    }
    --list->length;
  }
}

void DeleteElemFromList(LinkList list,int pos,int &elem)
{
  Link p,q;
  if(pos<1 || pos>ListLength(*list))
    cout<<"The position is invalidate."<<endl;
  else
  {
    if(pos==1)
    {
      DeleteElemFromHead(list,elem);
    }
    else if(pos==ListLength(*list))
    {
      DeleteElemFromEnd(list,elem);
    }
    else
    {
      q=list->head->next;//q指向第一个结点
      for(int i=1;i<pos-1;++i)
      {//找到第pos-1个结点
        q=q->next;
      }
      p=q->next;
      q->next=p->next;
      elem=p->value;
      free(p);
      --list->length;
    }
  }
}

bool PreElem(List list,int pos,int &elem)
{//返回pos位置处的前驱
  Link p=list.head->next;
  if(!IsEmptyList(list))
  {
    if(pos<1 || pos>ListLength(list))
    {
      cout<<"The position is invalidate."<<endl;
      return false;
    }
    else if(pos==1)
    {
      cout<<"This position doesn't have pre_element."<<endl;
      return false;
    }
    else
    {
      for(int i=1;i<pos-1;++i)
      {
        p=p->next; //找到pos-1位置
      }
      elem=p->value;
      return true;
    }
  }
}

bool NextElem(List list,int pos,int &elem)
{//返回pos位置处的后继
  Link p=list.head->next;
  if(!IsEmptyList(list))
  {
    if(pos<1 || pos>ListLength(list))
    {
      cout<<"The position is invalidate."<<endl;
      return false;
    }
    else if(pos==ListLength(list))
    {
      cout<<"This position doesn't have next_element."<<endl;
      return false;
    }
    else
    {
      for(int i=1;i<pos;++i)
      {
        p=p->next;//找到pos位置
      }
      elem=p->next->value;
      return true;
    }
  }
}

bool CurrentElem(List list,int pos,int &elem)
{//得到pos位置处的元素
  Link p=list.head->next;
  if(!IsEmptyList(list))
  {
    if(pos<1 || pos>ListLength(list))
    {
      cout<<"The position is invalidate."<<endl;
      return false;
    }
    else
    {
      for(int i=1;i<pos;++i)
      {
        p=p->next;//找到pos位置
      }
      elem=p->value;
      return true;
    }
  }
}

bool GetHead(List list,int &elem)
{//如果链表不空,则返回表头元素,用elem接收
  if(IsEmptyList(list))
  {
    cout<<"The list is empty."<<endl;
    return false;
  }
  else
  {
    elem=list.head->next->value;
    return true;
  }
}

bool GetTail(List list,int &elem)
{//如果链表不空,则返回表尾元素,用elem接收
  if(IsEmptyList(list))
  {
    cout<<"The list is empty."<<endl;
    return false;
  }
  else
  {
    elem=list.tail->value;
    return true;
  }
}

void ClearList(LinkList list)
{//清空链表并释放所有结点空间
  if(!IsEmptyList(*list))
  {
    Link p=list->head->next; //p指向第一个结点
    Link q;
    while(p!=list->tail)
    {//释放每个结点空间
      q=p->next;
      free(p);
      p=q;
    }
    free(p);//释放尾结点
    list->length=0;
  }
}

void DestroyList(LinkList list)
{//销毁链表
  ClearList(list);//先清空链表
  free(list->head);//释放头结点
}

void VistElemOfList(List list)
{//遍历链表,输出链表元素
  Link p;
  p=list.head->next;
  if(!IsEmptyList(list))
  {
    while(p)
    {
      cout<<p->value<<' ';
      p=p->next;
    }
  }
        cout<<endl;
}
    测试代码:
   
#include "stdafx.h"
#include <conio.h>
#include "list.h"


int _tmain(int argc, _TCHAR* argv[])
{
  LinkList list;
  list=NewList();
  if(IsEmptyList(*list))
    cout<<"The list is empty."<<endl;
  cout<<"The length of the list is:"<<ListLength(*list)<<endl;
  InsertElemToHead(list,5);
  InsertElemToHead(list,9);
  ClearList(list);
  cout<<"The address of head is:"<<list->head<<endl;
  InsertElemToHead(list,8);
  InsertElemToEnd(list,10);
  InsertElemToEnd(list,22);
  InsertElemToEnd(list,36);
  VistElemOfList(*list);
  int e;
  if(GetHead(*list,e))
  {
    cout<<"The head_elem of the list is:"<<e<<endl;
  }
  if(GetTail(*list,e))
  {
    cout<<"The head_elem of the list is:"<<e<<endl;
  }
  cout<<"The length of the list is:"<<ListLength(*list)<<endl;
  InsertElemToList(list,3,21);
  InsertElemToList(list,1,88);
  InsertElemToList(list,8,99);
  InsertElemToList(list,10,100);
  VistElemOfList(*list);
  cout<<"The length of the list is:"<<ListLength(*list)<<endl;
  int elem;
  DeleteElemFromEnd(list,elem);
  VistElemOfList(*list);
        cout<<"The length of the list is:"<<ListLength(*list)<<endl;
  DeleteElemFromHead(list,elem);
  VistElemOfList(*list);
  cout<<"The length of the list is:"<<ListLength(*list)<<endl;
  if(GetHead(*list,e))
  {
    cout<<"The head_elem of the list is:"<<e<<endl;
  }
  if(GetTail(*list,e))
  {
    cout<<"The head_elem of the list is:"<<e<<endl;
  }
  DeleteElemFromList(list,4,elem);
  VistElemOfList(*list);
  cout<<"The length of the list is:"<<ListLength(*list)<<endl;
  DeleteElemFromList(list,1,elem);
  VistElemOfList(*list);
  cout<<"The length of the list is:"<<ListLength(*list)<<endl;
  DeleteElemFromList(list,ListLength(*list)+1,elem);
  VistElemOfList(*list);
  int temp;
  if(PreElem(*list,1,temp))
  {
    cout<<"The pre_element of this position is:"<<temp<<endl;
  }
  if(PreElem(*list,2,temp))
  {
    cout<<"The pre_element of this position is:"<<temp<<endl;
  }
  if(NextElem(*list,1,temp))
  {
    cout<<"The next_element of this position is:"<<temp<<endl;
  }
  if(NextElem(*list,ListLength(*list),temp))
  {
    cout<<"The next_element of this position is:"<<temp<<endl;
  }
  if(CurrentElem(*list,2,temp))
  {
    cout<<"The cur_element of this position is:"<<temp<<endl;
  }
  if(CurrentElem(*list,12,temp))
  {
    cout<<"The cur_element of this position is:"<<temp<<endl;
  }
  ClearList(list);
  VistElemOfList(*list);
  getch();
  return 0;
}