抽象数据类型(ADT) 双链表实现

/*main.c----测试函数*/
#include<stdio.h>
#include<stdlib.h>
#include"list.h"
static void show(const ITEM * item)
{
printf("Film's name:%-20sRating:%-2d\n",item->title,item->rating);
}
int main(void)
{
LIST plist;
char input[TSIZE];
int rating;
ITEM eitem;
InitializeList(&plist);
puts("Enter first movie title:");
while(gets(input)!=NULL && input[0] != '\0')
{
strcpy(eitem.title,input);
puts("Enter your rating<0-10>:");
scanf("%d",&(eitem.rating));
while(getchar() != '\n') continue;
AddItem(&eitem,&plist);
puts("Enter next movie title(empty line to stop):");
}
Traverse(&plist,show,0);
putchar('\n');
Traverse(&plist,show,1);
system("pause");
return 0;
}

/*list.c----定义接口*/
#ifndef LIST_H_INCLUDED
#define LIST_H_INCLUDED
#include<stdio.h>
#include<stdbool.h>
#define TSIZE 45
#define ITEMSIZE 10
struct film
{
char title[TSIZE];
int rating;
};
typedef struct film ITEM;
typedef struct node
{
ITEM item;
struct node *next;
struct node *previous;
}NODE;
typedef struct list
{
NODE *head;
NODE *end;
int count;
}LIST;
void InitializeList(LIST *plist);
bool ListIsEmpty(const LIST *plist);
bool ListIsFull(const LIST * plist);
int ListItemCount(const LIST * plist);
bool AddItem(ITEM *item,LIST * plist);
void Traverse(const LIST * plist,void (*pfun)(const ITEM * item),int direction);
#endif // LIST_H_INCLUDED

/*list.c实现接口*/
#include"list.h"
#include<stdio.h>
static void CopyToNode(NODE *pnode,ITEM *pitem);
void InitializeList(LIST *plist)
{
plist->head = NULL;
plist->end = NULL;
plist->count = 0;
}
bool ListIsEmpty(const LIST *plist)
{
if(plist->count == 0)
return true;
else
return false;
}
bool ListIsFull(const LIST * plist)
{
if(plist->count == ITEMSIZE)
return true;
else
return false;
}
int ListItemCount(const LIST * plist)
{
return plist->count;
}
bool AddItem(ITEM *item,LIST * plist)
{
NODE *pnode;
if(ListIsFull(plist))
{
printf("List full!\n");
return false;
}
pnode = (NODE*)malloc(sizeof(NODE));
if(pnode == NULL)
{
printf("Disk full!\n");
return false;
}
else
CopyToNode(pnode,item);
if(plist->head == NULL)
plist->head = pnode;
else
{
plist->end->next = pnode;
pnode->previous = plist->end;
}
plist->end = pnode;
plist->count++;
}
void Traverse(const LIST * plist,void (*pfun)(const ITEM * item),int direction)
{
int i;
LIST current = *plist;
if(ListIsEmpty(plist))
{
printf("List is empty!\n");
return;
}
if(direction == 0)
{
while(current.head != NULL)
{
(*pfun)(&(current.head->item));
current.head = current.head->next;
}
}
else
{
while(current.end != NULL)
{
(*pfun)(&(current.end->item));
current.end = current.end->previous;
}
}
printf("Here are %d movie.\n",ListItemCount(plist));
}
static void CopyToNode(NODE *pnode,ITEM *pitem)
{
pnode->item = *pitem;
pnode->next = NULL;
pnode->previous = NULL;
}