结构指针应用例题

 1 /*修改学生成绩，结构指针作为函数参数*/
 2 #include <stdio.h>
 3 struct student
 4 {
 5     int num;
 6     char name[10];
 7     int computer, english, math;
 8     double average;
 9 };
10 int update_score(struct student *p, int n, int num, int course, int score);
11 int main(void)
12 {
13     int course, i, n, num, pos, score;
14     struct student students[50];
15 
16     printf("Input n:");
17     scanf("%d", &n);
18     for (i = 0; i < n; i++)
19     {
20         printf("Input the info of No.%d:\n", i + 1);
21         printf("number:");
22         scanf("%d", &students[i].num);
23         printf("name:");
24         scanf("%s", students[i].name);
25         printf("math score:");
26         scanf("%d", &students[i].math);
27         printf("english score:");
28         scanf("%d", &students[i].english);
29         printf("computer score:");
30         scanf("%d", &students[i].computer);
31     }
32 
33     printf("Input the number of the students to be updated:");
34     scanf("%d", &num);
35     printf("Choice the course:1.math 2.english 3.computer:");
36     scanf("%d", &course);
37     printf("Input the new score:");
38     scanf("%d", &score);
39 
40     pos = update_score(students, n, num, course, score);
41 
42     if (pos == -1)
43     {
44         printf("Not found!\n");
45     }
46     else
47     {
48         printf("After update:\n");
49         printf("%d\t%d\t%d\t%d\n", students[pos].num, students[pos].math, students[pos].english, students[pos].computer);
50     }
51 
52     return 0;
53 }
54 int update_score(struct student *p, int n, int num, int course, int score)
55 {
56     int i, pos;
57     for (i = 0; i < n; i++, p++)
58     {
59         if (p->num == num)
60         {
61             break;
62         }
63     }
64     if (i < n)
65     {
66         switch (course)
67         {
68         case 1:
69             p->math = score;
70             break;
71         case 2:
72             p->english = score;
73             break;
74         case 3:
75             p->computer = score;
76             break;
77         }
78         pos = i;
79     }
80     else
81     {
82         pos = -1;
83     }
84 
85     return pos;
86 }