看书也有点搞不懂。希望。我希望比较厉害的大神们举个例子，举个例子代码，然后讲思路。比如下面串代码
* films3.c -- 使用抽象数据类型（ADT）风格的链表 */
/* 与list.c一起编译                        */
#include <stdio.h>
#include <stdlib.h>    /* 提供exit()的原型 */
#include "list.h"      /* 定义List、Item   */
void showmovies(Item item);
char * s_gets(char * st, int n);
int main(void)
{
    List movies;
    Item temp;

    /* 初始化       */
    InitializeList(&movies);
    if (ListIsFull(&movies))
    {
   fprintf(stderr, "No memory available! Bye!\n");
        exit(1);
    }

    /* 获取用户输入并储存 */
    puts("Enter first movie title:");
    while (s_gets(temp.title, TSIZE) != NULL && temp.title[0] != '\0')
    {
        puts("Enter your rating <0-10>:");
        scanf("%d", &temp.rating);
        while (getchar() != '\n')
            continue;
        if (AddItem(temp, &movies) == false)
        {
            fprintf(stderr, "Problem allocating memory\n");
            break;
        }
   fprintf(stderr, "No memory available! Bye!\n");
        exit(1);
    }

    /* 获取用户输入并储存 */
    puts("Enter first movie title:");
    while (s_gets(temp.title, TSIZE) != NULL && temp.title[0] != '\0')
    {
        puts("Enter your rating <0-10>:");
        scanf("%d", &temp.rating);
        while (getchar() != '\n')
            continue;
        if (AddItem(temp, &movies) == false)
        {
            fprintf(stderr, "Problem allocating memory\n");
            break;
        }
略一百行代码.我也特别想知道怎么实现接口,使用接口的写代码流程