链表（一） 单向链表

 1 #include <stdio.h>
 2 #include <stdlib.h>      /* has the malloc prototype      */
 3 #include <string.h>      /* has the strcpy prototype      */
 4 #define TSIZE    45      /* size of array to hold title   */
 5 
 6 struct film {
 7     char title[TSIZE];    // 书名
 8     int rating;           // 评分
 9     struct film * next;  // 指向链表的下一个结构
10 };
11 
12 
13 
14 int main(void)
15 {
16     struct film * head = NULL;                // 头指针      
17     struct film * prev, * current;            // 前指针   当前指针
18     char input[TSIZE];
19 
20 /* Gather  and store information          */  //收集并保存信息
21     puts("Enter first movie title:");
22 
23 
24     while (gets(input) != NULL && input[0] != ‘\0‘)          // input  0x12ff44 存放书名 great expections 
25     {
26         current = (struct film *) malloc(sizeof(struct film));       //  &current=0x0012ff74   current=0x00431d70       第二次 current=0x431d00
27         if (head == NULL)       /* first structure       */
28             head = current;                                 //  把 current 指向的地址 传给 head指针，那么 head=0x00431d70   
29         else                    /* subsequent structures */
30             prev->next = current;                                                                                     //   prev->next=0x431d00 
31         
32         current->next = NULL;                         //  表示当前结构是列表中的最后一个
33         strcpy(current->title, input);               //  &current->title=0x00431d70  "great exception "   current->title= 0x00431d70 
34         puts("Enter your rating <0-10>:");
35 
36         scanf("%d", &current->rating);               // &current->rating=0x00431da0  "8"          current->rating=  8
37        
38         
39         while(getchar() != ‘\n‘)
40             continue;
41         puts("Enter next movie title (empty line to stop):");
42         prev = current;                           // &prev = 0x0012ff78  prev=0x00431d70 
43    
44     }
45 
46 
47 /* Show list of movies                    */
48     if (head == NULL)
49         printf("No data entered. ");
50     else
51         printf ("Here is the movie list:\n");
52     
53     current = head;                   // &current=0x0012ff74  current=0x00431d70   也就是 开始  
54     while (current != NULL)
55     {
56         printf("Movie: %s  Rating: %d\n", 
57                current->title, current->rating);
58         current = current->next;      // 指向下一个指针
59     }
60 
61     current=head;                    // 从开头指针 开始释放。
62     while(current != NULL)
63     {
64         free(current);
65         current=current->next;
66         
67     }
68     printf("Bye !\n");
69   
70 
71    return 0;
72 
73 }