实验七 文件应用编程

实验任务4

 1 #include <stdio.h>
 2 
 3 int main() {
 4     int count = 0;
 5     int ch;
 6     FILE *fp;
 7 
 8     fp = fopen("data4.txt", "r");
 9     if (fp == NULL) {
10         printf("fail to open file\n");
11         return 1; 
12     }
13 
14     while ((ch = fgetc(fp)) != EOF) {
15         if (!(ch == ' ' || ch == '\n' || ch == '\t')) {
16             count++;
17         }
18     }
19 
20     printf("data4.txt中共包含字符数（不记空白符）：%d\n", count);
21 
22     fclose(fp);
23 
24     return 0;
25 }

实验任务5

  1 #include <stdio.h>
  2 #include <string.h>
  3 #include <stdlib.h>
  4 
  5 #define N 10
  6 
  7 typedef struct {
  8     long int id;
  9     char name[20];
 10     float objective;    // 客观题得分
 11     float subjective;   // 操作题得分
 12     float sum;          // 总分
 13     char ans[10];       // 考试结果
 14 } STU;
 15 
 16 // 函数声明
 17 void finput(STU st[], int n);
 18 void foutput(STU st[], int n);
 19 void output(STU st[], int n);
 20 int process(STU st[], int n, STU st_pass[]);
 21 
 22 int main() {
 23     STU stu[N], stu_pass[N];
 24     int cnt;
 25     double pass_rate;
 26 
 27     printf("从文件读入%d个考生信息...\n", N);
 28     finput(stu, N);
 29 
 30     printf("\n对考生成绩进行统计...\n");
 31     cnt = process(stu, N, stu_pass);
 32 
 33     printf("\n通过考试的名单:\n");
 34     output(stu_pass, cnt);      // 输出到屏幕
 35     foutput(stu_pass, cnt);    // 输出到文件
 36 
 37     pass_rate = 1.0 * cnt / N;
 38     printf("\n本次等级考试通过率: %.2f%%\n", pass_rate*100);
 39     
 40     return 0;
 41 }
 42 
 43 // 把通过考试的考生完整信息输出到屏幕上
 44 // 准考证号，姓名，客观题得分，操作题得分，总分，结果
 45 void output(STU st[], int n) {
 46     int i;
 47     
 48     printf("准考证号\t姓名\t客观题得分\t操作题得分\t总分\t\t结果\n");
 49     for (i = 0; i < n; i++)
 50         printf("%ld\t\t%s\t%.2f\t\t%.2f\t\t%.2f\t\t%s\n", st[i].id, st[i].name, st[i].objective, st[i].subjective, st[i].sum, st[i].ans);
 51 }
 52 
 53 // 从文本文件examinee.txt读入考生信息:准考证号，姓名，客观题得分，操作题得分
 54 void finput(STU st[], int n) {
 55     int i;
 56     FILE *fin;
 57 
 58     fin = fopen("examinee.txt", "r");
 59     if (fin == NULL) {
 60         printf("fail to open file\n");
 61         exit(0);
 62     }
 63 
 64     while (!feof(fin)) {
 65         for (i = 0; i < n; i++)
 66             fscanf(fin, "%ld %s %f %f", &st[i].id, st[i].name, &st[i].objective, &st[i].subjective);
 67     }
 68 
 69     fclose(fin);
 70 }
 71 
 72 // 把通过考试的考生完整信息写入文件list_pass.txt
 73 // 准考证号，姓名，客观题得分，操作题得分，总分，结果
 74 void foutput(STU s[], int n) {
 75     FILE *fout;
 76     int i;
 77     
 78     // 保存到文件 
 79     fout = fopen("list_pass.txt", "w");
 80     if (!fout) {
 81         printf("fail to open or create list_pass.txt\n");
 82         exit(0);
 83     }
 84     
 85     fprintf(fout, "准考证号\t\t姓名\t客观题得分\t操作题得分\t总分\t\t结果\n");
 86 
 87     for (i = 0; i < n; i++)
 88         fprintf(fout, "%ld\t\t%s\t%.2f\t\t%.2f\t\t%.2f\t\t%s\n", s[i].id, s[i].name, s[i].objective, s[i].subjective, s[i].sum, s[i].ans);
 89 
 90     fclose(fout);
 91 }
 92 
 93 // 对考生信息进行处理：计算每位考生考试总分、结果；统计考试通过的人数
 94 int process(STU st[], int n, STU st_pass[]) {
 95    // 待补足
 96    // ×××
 97     int i,count = 0;
 98 
 99     for (i = 0; i < n; i++){
100         st[i].sum = st[i].objective + st[i].subjective;
101         if(st[i].sum >= 60){
102             strcpy(st[i].ans,"pass");
103             st_pass[count++] = st[i];
104         }
105         else
106             strcpy(st[i].ans,"fail");
107     }
108 
109     return count;
110 }

实验任务6

 1 #include <stdio.h>
 2 #include <stdlib.h>
 3 #include <time.h>
 4 
 5 #define N 100
 6 
 7 struct STU {
 8     long int id;
 9     char name[N];
10     char cla[N];
11 } st[N], lucky[N];
12 
13 void func1(void);
14 int func2(void);
15 void func3(void);
16 
17 int main() {
18     int j, n;
19     func1(); 
20 
21 
22     srand((unsigned)time(NULL)); 
23 
24     for (j = 0; j < 5; j++) {
25         n = func2();
26         lucky[j] = st[n];
27         printf("%ld\t %s\t %s\t\n", lucky[j].id, lucky[j].name, lucky[j].cla);
28     }
29 
30     func3(); 
31 
32     getchar(); 
33 
34     return 0;
35 }
36 
37 void func1(void) {
38     int i;
39     FILE *fp;
40 
41     fp = fopen("list.txt", "r");
42 
43     if (fp == NULL) {
44         printf("Failed to open file\n");
45         return;
46     }
47 
48     i = 0;
49     while (fscanf(fp, "%ld\t %s\t %s\t", &st[i].id, st[i].name, st[i].cla) == 3 && i < N) {
50         ++i;
51     }
52 
53     fclose(fp);
54 }
55 
56 int func2(void) {
57     return rand() % 80; 
58 }
59 
60 void func3(void) {
61     int j;
62     FILE *fout;
63 
64     fout = fopen("lucky.txt", "w");
65 
66     if (fout == NULL) {
67         printf("Failed to open file\n");
68         return;
69     }
70 
71     for (j = 0; j < 5; j++) { 
72         fprintf(fout, "%ld %s %s\n", lucky[j].id, lucky[j].name, lucky[j].cla); 
73     }
74 
75     fclose(fout);
76 }