实验7 文件应用编程

实验7 文件应用编程

实验任务4

实验程序

#include <stdio.h>
#include <string.h>
#define _CRT_SECURE_NO_WARNINGS
#define N 10

typedef struct {
    long id;
    char name[20];
    float objective;
    float subjective;
    float sum;
    char result[10];
} STU;

void read(STU st[], int n);
void write(STU st[], int n);
void output(STU st[], int n);
int process(STU st[], int n, STU st_pass[]);

int main() {
    STU stu[N], stu_pass[N];
    int cnt;
    double pass_rate;

    printf("从文件读入%d个考生信息...\n", N);
    read(stu, N);

    printf("\n对考生成绩进行统计...\n");
    cnt = process(stu, N, stu_pass);

    printf("\n通过考试的名单:\n");
    output(stu, N);
    write(stu, N);

    pass_rate = 1.0 * cnt / N;
    printf("\n本次等级考试通过率: %.2f%%\n", pass_rate * 100);
    getchar();
    getchar();
    return 0;
}
void output(STU st[], int n) {
    int i;

    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");
    for (i = 0; i < n; i++)
        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].result);
}


void read(STU st[], int n) {
    int i;
    FILE* fin;

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

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

    fclose(fin);
}
void write(STU s[], int n) {
    int i;
    FILE* fin;

    fin = fopen("D:\C语言任务\list.txt", "w");
    if (!fin) {
        printf("fail to open file\n");
        return;
    }

    fprintf(fin, "准考证号\t姓名\t\t客观题得分\t\t操作题得分\t\t总分\t\t结果\n");
    for (i = 0; i < n; i++) {
        if (s[i].sum >= 60)
            fprintf(fin, "%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].result);
    }
    fclose(fin);
}
int process(STU st[], int n, STU st_pass[]) {
    int passnum = 0;
    int i;
    int j = 0;
    for (i = 0; i < n; i++) {
        st[i].sum = st[i].subjective + st[i].objective;
        if (st[i].sum >= 60) {
            strcpy(st[i].result, "通过");

            st_pass[j] = st[i];
            j++;
            passnum++;
        }
        else
            strcpy(st[i].result, "不通过");

    }
    return passnum;
}

运行结果

实验任务6

实验程序

#include <stdio.h>
#include <stdlib.h>
#include <time.h>
#include <string.h>
#define N 80
int main() {
    char info[N][80];
    char outfilename[N];
    char list[5][N];
    FILE* fp;
    FILE* outfp;
    int lucky_index,i;

    fp = fopen("list.txt", "r");
    if (!fp) {
        printf("保存失败\n");
        return 1;
    }
    for (i = 0; i < 80; i++) {
        fgets(info[i], 80, fp);
        printf("%s", info[i]);
    }
    fclose(fp);

    srand(time(NULL));
    printf("\n-----------------中奖名单-----------------\n");
    for (i = 0; i < 5; i++) {
        lucky_index = rand() % N;
        printf("%s", info[lucky_index]);
        strcpy(list[i], info[lucky_index]);
    }
    printf("\n--------保存到文件--------\n");
    printf("输入文件名: ");
    scanf("%99s", outfilename);
    outfp = fopen(outfilename, "w");
    if (!outfp) {
        printf("fail to open file to write\n");
        return 1;
        }
    for(i=0;i<5;i++){
        fprintf(outfp, "%s", list[i]);
    }
    printf("保存成功!");
    fclose(outfp);
    return 0;
}

运行结果