单链表的基本操作

头文件
#ifndef _LIST_H  
#define _LIST_H  
	  
#include<iostream>  
#include<assert.h>  
using namespace std;  
	  
#define ElemType int  
	  
typedef struct Node  
{  
   ElemType data;  
   struct Node *next;  
}Node, *PNode;  
	  
typedef struct List  
{  
   PNode first;  
   PNode last;  
   size_t size;  
}List;  
void InitList(List *list);//初始化  
bool push_back(List *list, ElemType x);//尾插  
bool push_front(List *list, ElemType x);//头插  
bool pop_back(List *list);//尾删  
bool pop_front(List *list);//头删  
Node* Find(List *list, ElemType key);//按值找地址  
Node* FindPrio(List *list, ElemType key);//按值找前驱地址  
bool insert_val(List *list, ElemType key,ElemType x);//按值找位置并插入值  
bool delete_val(List *list, ElemType key);//按值找值删除  
bool modify(List *list, ElemType key,ElemType x);//按值找值修改  
void ShowList(List *list);//打印  
void clear(List *list);//清除  
void destroy(List *list);//摧毁   
void resver(List *list);//逆置（值不相同）  
int length(List *list);//长度  
ElemType Next(List *list , ElemType key);//后继的值  
ElemType Prio(List *list , ElemType key);//前驱的值 
void sort(List *list);//排序 
#endif  
各个函数的定义
#include "List.h"
void InitList(List *list)  
{  
   Node *s = (Node *)malloc(sizeof(Node));  
   assert(s != NULL);
   s->next = NULL;  
 
   list->first = list->last = s;  
   list->size = 0;  
} 
 Node* Find(List *list, ElemType key)  
{  
  Node *p = list->first->next;  
  while(p != NULL && p->data != key)  
  {  
       p = p->next;  
  }  
    return p;  
}  
bool push_back(List *list, ElemType x)  
{  
    Node *s = (Node *)malloc(sizeof(Node));  
    if(s == NULL)  
	{  
        return false;  
	}  
   s->data = x;  
   s->next = NULL;  
  
   list->last ->next = s;  
   list->last = s; 
   list->size++;  
   return true;  
}  

bool push_front(List *list, ElemType x)  
{  
  Node *s = (Node *)malloc(sizeof(Node));  
    if(s == NULL)  
    {  
       return false;  
    }  
    s->data = x;  
    s->next = list->first->next ;  
    list->first->next = s;  
    if(list->size == 0)  
    {  
        list->last = s;  
    }  
    list->size ++;  
    return true;  
} 
bool pop_back(List *list)  
{  
   if(list->size == 0)  
   {  
      return false;  
   }  
   Node *pre = list->first ;  
   while(pre->next != list->last)  
   {  
      pre = pre->next ;  
   }  
  pre->next = NULL;  
  free(list->last);  
  list->last = pre;  
  list->size--;  
  return true;  
}  
bool pop_front(List *list)  
{  
  if(list->size == 0)  
  {  
      return false;  
   }  
  Node *p = list->first->next ;  
  if(list->size == 1)  
    {  
      free(p);  
      list->first->next = NULL;  
      list->last = list->first ;  
   }  
    else  
    {  
       list->first->next = p->next ;  
       free(p);  
	}  
   list->size--;  
   return true;  
}  
void ShowList(List *list)  
{  
     Node *p = list->first ->next ;  
     while(p != NULL)  
	    {  
	        cout<<p->data <<"-->";  
            p = p->next ;  
	    }  
	    cout<<"NULL"<<endl;  
} 
 bool insert_val(List *list, ElemType key,ElemType x)  
{  
    Node *pos = Find(list,key);  
    if(pos == NULL)  
	{  
         return false;  
	}  
    Node *s = (Node *)malloc(sizeof(Node));  
    s->data = x;  
    s->next = pos->next ;  
	  pos->next = s;  
    return true;
 }
bool delete_val(List *list, ElemType key)  
{  
     Node *pos = FindPrio(list,key);  
     if(pos == NULL)  
	    {  
	       return false;  
	    }  
	    Node *s = pos->next;  
	    pos->next = s->next;  
	    free(s);  
	    list->size--;  
	    return true;  
} 
 

Node* FindPrio(List *list, ElemType key)  
{  
  Node *pre = list->first;  
  Node *p = pre->next ;  
	 while(p !=NULL && p ->data!=key)  
	 {  
       p = p->next;  
	   pre = pre->next;  
	 }  
	    return pre;  
}
void clear(List *list)  
{  
	Node *p = list->first->next;  
    while(p != NULL)  
	    {  
	        list->first->next = p->next;  
            free(p);  
	        p = list->first->next;  
	    }  
	  list->first = list->last ;  
	  list->size  = 0;   
}  
  

bool modify(List *list, ElemType key,ElemType x)  
{  
   Node *pos = Find(list,key);  
   if(pos == NULL)  
    {  
	   return false;  
   }  
    pos->data = x;  
    return true;  
}
void destroy(List *list)  
{  
	    clear(list);  
	    free(list->first);  
	    list->first = list->last = NULL;  
} 
 int length(List *list)  
{  
    return list->size;  
} 
 void resver(List *list)//数值不重复  
{  
   Node* s = (Node*)malloc(sizeof(Node));  
   if(list->size == 0)  
    {  
        return ;  
    }  
  if(list->size == 1)  
  {  
	       cout<<"逆置后值为:"<<list->last->data <<endl;  
  }  
	    s->next = list->last ;  
	    while(list->first->next != list->last)  
	    {  
	        list->last->next = FindPrio(list,list->last->data);  
	        list->last = list->last->next;  
		}  
	    list->last->next = NULL;  
	    free(list->first);  
	    list->first = s;  
}  
ElemType Next(List *list , ElemType key)  
{  
   Node *pos = Find(list,key);  
   if(pos == NULL)  
	    {  
	        return -1;  
	    }  
    return pos->next->data;  
}  
ElemType Prio(List *list , ElemType key)  
{  
    Node* pos = FindPrio(list,key);  
    if(pos == NULL)  
	    {  
	       return -1;  
	    }  
	return pos->data;  
} 
 

void sort(List *list)//数值不重复  
  {  
     int count = list->size;  
     Node *pre = list->first->next;  
     Node *p = pre->next;  
     if(list->size == 0)  
	    {  
	        return ;  
	    }  
    if(list->size == 1)  
	    {  
	        cout<<"排序后为:"<<list->last->data<<endl;  
	    }  
      while(count)  
	  {  
       if(p->data >= pre->data )  
	   {  
         p = p->next ;  
         pre = pre->next ;  
       }  
        else  
        {  
           ElemType item = p->data;  
           p->data = pre->data ;  
           pre->data = item;  
		}  
	    count--;
	  }
}
测试函数
#include "List.h"
void main()  
{  
   List mylist;  
   InitList(&mylist);  
   int select = 1;  
   ElemType item;  
   ElemType pos;  
   Node *p = NULL;  
  while(select)  
  {  
     cout<<"************************************"<<endl;  
     cout<<"* [0]  quit_system [1] push_back   *"<<endl;  
     cout<<"* [2]  push_front  [3] show_seqlist*"<<endl;  
     cout<<"* [4]  pop_back    [5] pop_front   *"<<endl;  
     cout<<"* [6]  insert_val  [7] delete_val  *"<<endl;  
     cout<<"* [8]  findprio    [9] modify      *"<<endl;  
     cout<<"* [10] sort       [11] clear       *"<<endl;  
     cout<<"* [12] destroy    [13] length      *"<<endl;  
	 cout<<"* [14] resver     [15] next        *"<<endl;  
     cout<<"* [16] prio       [17] find        *"<<endl;  
     cout<<"************************************"<<endl;  
     cout<<"请选择:>";  
     cin>>select;  
     switch(select)  
     {  
     case 1:  
        cout<<"请输入要插入的数据(-1结束):>";  
        while(cin>>item,item!=-1)  
		{  
           push_back(&mylist,item);  
         }  
         break;  
	 case 2:  
       cout<<"请输入要插入的数据(-1结束):>";  
       while(cin>>item,item!=-1)  
	   {  
           push_front(&mylist,item);  
       }  
       break;
	   
     case 3:  
       ShowList(&mylist);  
        break;  
     case 4:  
       pop_back(&mylist);  
        break;  
     case 5:  
       pop_front(&mylist);  
         break;
		 
     case 6:  
         cout<<"请输入在何值后插入值:>";  
         cin>>item;  
         cout<<"请输入要插入的值:>";  
         cin>>pos;  
         insert_val(&mylist,item,pos);  
         break;  

     case 7:  
     cout<<"请输入要删除的值:>";  
	 cin>>item;  
     delete_val(&mylist,item);  
     break; 
	 case 8:  
	     cout<<"请输入要查找的值:>";  
         cin>>item;  
         p = FindPrio(&mylist,item);  
        cout<<"所在查找值的前驱地址为:"<<p<<endl;  
        break;  
    case 9:  
        cout<<"请输入要修改的值:>";  
        cin>>item;  
        cout<<"请输入改变后的值:>";  
        cin>>pos;  
		modify(&mylist,item,pos);  
        break; 
    case 10:  
       sort(&mylist);  
       break;  
    case 11:  
      clear(&mylist);  
       break;  
     case 12:  
       destroy(&mylist);  
	   break; 
	   
    case 13:  
      cout<<"单链表的长度为："<<length(&mylist)<<endl;
	  break;  
    case 14:  
		resver(&mylist);  
         break;  
    case 15:  
       cout<<"请输入要查找的值:>";  
	   cin>>item;  
	   cout<<"所在查找值的后继为:"<<Next(&mylist,item)<<endl;  
	   break;
	   
	   
    case 16:  
        cout<<"请输入要查找的值:>";  
        cin>>item;  
        cout<<"所在查找值的前驱为:"<<Prio(&mylist,item)<<endl;  
       break;  
    

     case 17:  
			cout<<"请输入要查找的值:>";  
            cin>>item;  
            p = Find(&mylist,item);  
            cout<<"所在查找值的地址为:"<<p<<endl;  
            break;
     default:  
            break;
	 }
  }
}