实验6 文件应用编程

 1 #define _CRT_SECURE_NO_WARNINGS
 2 #include<stdio.h>
 3 int main()
 4 {
 5     int num=0;
 6     FILE* fp;
 7     char ch;
 8     if ((fp = fopen("data4.txt", "r"))==NULL)
 9         printf("fail to open it");
10     ch = fgetc(fp);
11     while (!feof(fp))
12     {
13         if (ch != ' ' &&  ch!= '\n' )
14             num++;
15         ch = fgetc(fp);
16     }
17     fclose(fp);
18     printf("%d", num);
19 }

#define _CRT_SECURE_NO_WARNINGS
#include <stdio.h>
#include <string.h>
#include <stdlib.h>

#define N 10

typedef struct {
    long int id;
    char name[20];
    float objective;    // 客观题得分
    float subjective;   // 操作题得分
    float sum;
    char level[10];
} STU;

// 函数声明
void input(STU s[], int n);
void output(STU s[], int n);
void process(STU s[], int n);

int main() {
    STU stu[N];

    printf("从文件读入%d个考生信息: 准考证号，姓名，客观题得分(<=40)，操作题得分(<=60)\n", N);
    input(stu, N);

    printf("\n对考生信息进行处理: 计算总分，确定等级\n");
    process(stu, N);

    printf("\n打印考生完整信息, 并保存到文件中");
    output(stu, N);

    return 0;
}

// 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
void input(STU s[], int n) {
    int i;
    FILE* fin;

    fin = fopen("examinee.txt", "r");
    if (fin == NULL) {
        printf("fail to open file\n");
        exit(0);
    }

    while (!feof(fin)) {
        for (i = 0; i < n; i++)
            fscanf(fin, "%ld %s %f %f", &s[i].id, s[i].name, &s[i].objective, &s[i].subjective);
    }

    fclose(fin);
}

// 输出考生完整信息: 准考证号，姓名，客观题得分，操作题得分，总分，等级
// 不仅输出到屏幕上，还写到文本文件result.txt中
void output(STU s[], int n) {
    FILE* fout;
    int i;

    // 输出到屏幕
    printf("\n");
    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等级\n");
    for (i = 0; i < n; i++)
        printf("%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].level);

    // 保存到文件 
    fout = fopen("result.txt", "w");
    if (!fout) {
        printf("fail to open or create result.txt\n");
        exit(0);
    }

    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等级\n");

    for (i = 0; i < n; i++)
        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].level);

    fclose(fout);
}

// 对考生信息进行处理：计算总分，排序，确定等级
void process(STU s[], int n)
{
    STU temp;
    int i, j, k;

    for (i = 0; i < N; i++)
    {
        s[i].sum = s[i].objective  + s[i].subjective ;
    }
    for (i = 0; i < N - 1; i++)
    {
        for (j = 0; j < N - i - 1; j++)
        {
            if (s[j].sum < s[j + 1].sum)
            {
                temp = s[j + 1];
                s[j + 1] = s[j];
                s[j] = temp;
            }
        }
    }
    for (k = 0; k < N; k++)
    {
        switch (k)
        {
        case 0:strcpy(s[k].level, "优秀"); break;
        case 1:
        case 2:
        case 3:
        case 4:strcpy(s[k].level, "合格"); break;
        case 5:
        case 6:
        case 7:
        case 8:
        case 9:strcpy(s[k].level, "不合格"); break;
        }
    }
}

 1 #define _CRT_SECURE_NO_WARNINGS
 2 #include<stdio.h>
 3 #include<stdlib.h>
 4 #include<time.h>
 5 #include<string.h>
 6 #define N 80
 7 #define M 5
 8 typedef struct 
 9 {
10     long no;
11     char name[10];
12     char class[20];
13 }STU;
14 int main()
15 {
16     STU list[N],lucky[M];
17     FILE* fp1,*fp2;
18     int i,j,random;
19     if ((fp1 = fopen("list.txt", "r")) == NULL)
20         printf("fail to open it");
21     for (i = 0; i < N; i++)
22         fscanf(fp1, "%ld %s %s", &list[i].no, list[i].name, list[i].class);
23     fclose(fp1);
24     srand((unsigned int)time(NULL));
25     for (j = 0; j < M; j++)
26     {
27         random = rand() % N + 1;
28         lucky[j] = list[random];
29     }
30     if ((fp2 = fopen("lucky.txt", "w")) == NULL)
31         printf("fail to open it");
32     for (j = 0; j < M; j++)
33         fprintf(fp2, "%ld  %s   %s\n", lucky[j].no, lucky[j].name, lucky[j].class);
34     fclose(fp2);
35 }