7

4
#define _CRT_SECURE_NO_WARNINGS
#include<stdio.h>
#include<stdlib.h>
#define N  80
#define M 100
typedef struct {
    char name[N];
    char author[N];
}Book;
void write();
void read();
int main() {
    printf("测试1：把图书信息写入文本信息\n");
    write();
    printf("\n测试2：从文本文件读取图书信息，打印输出到屏幕\n");
    read();
    return 0;
}
void write() {
    Book x[] = { {"《雕塑家》", "斯科特.麦克劳德"},
                 {"《灯塔》", "克里斯多夫.夏布特"},
                 {"《人的局限性》", "塞缪尔.约翰生"},
                 {"《永不停步：玛格丽特.阿特伍德传》", "罗斯玛丽.沙利文"},
                 {"《大地之上》", "罗欣顿·米斯特里"},
                 {"《上学记》", "何兆武"},
                 {"《命运》", "蔡崇达"} };
    int n, i;
    FILE* fp;
    n = sizeof(x) / sizeof(x[0]);
    fp = fopen("date1.txt", "w");
    if (fp == NULL) {
        printf("fail to open file to write \n");
        return;
    }
    for (i = 0; i < n; ++i)
        fprintf(fp, "%-40s %-20s\n", x[i].name, x[i].author);
    fclose(fp);

}
void read() {
    Book x[N];
    int i, n;
    FILE* fp;
    fp = fopen("date1.txt", "r");
    if (fp == NULL) {
        printf("fail to oprn file to read\n");
        return;
    }
    i = 0;
    while (fscanf(fp, "%s%s", x[i].name, x[i].author) != EOF)
        ++i;
    n = i;
    for (i = 0; i < n; i++)
        printf("%d.%-40s%-20s\n", i + 1, x[i].name, x[i].author);
    fclose(fp);

}

5

#include <stdio.h>
#include <string.h>

#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 s[], 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_pass, cnt);  
    write(stu_pass, cnt); 

    pass_rate = 1.0 * cnt / N;
    printf("\n本次等级考试通过率: %.2f%%\n", pass_rate * 100);

    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("C:\\Users\\沈CL\\Desktop\\新建文件夹\\examinee.txt", "r");
    if (!fin) {
        printf("fail to open file\n");
        return;
    }

    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) {
    FILE *fout;
    int i;

    fout = fopen("list_pass.txt", "w");
    if (!fout) {
        printf("无法创建文件 list_pass.txt\n");
        return;
    }

    fprintf(fout, "准考证号\t姓名\t客观题得分\t操作题得分\t总分\t结果\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].result);
    }

    fclose(fout);
}
int process(STU st[], int n, STU st_pass[]) {
    int i, pass_cnt = 0;
    for (i = 0; i < n; i++) {
        st[i].sum = st[i].objective + st[i].subjective;
        if (st[i].sum >= 60) {
            strcpy(st[i].result, "通过");
            st_pass[pass_cnt] = st[i];
            pass_cnt++;
        } else {
            strcpy(st[i].result, "不通过");
        }
    }
    return pass_cnt;
}

6

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>

#define N 80
#define M 5

int main() {
    FILE *fin, *fout;
    char students[N][50];
    int flag[N] = {0};
    int chosen[M];
    char filename[100];
    int i, index, count = 0;

    fin = fopen("C:\\Users\\沈CL\\Desktop\\新建文件夹\\list.txt", "r");
    if (!fin) {
        printf("无法打开文件 list.txt\n");
        return 1;
    }
    for (i = 0; i < N; i++) {
        if (fgets(students[i], 50, fin) == NULL) break;

        students[i][strcspn(students[i], "\n")] = 0;
    }
    fclose(fin);

    srand(time(NULL));

    while (count < M) {
        index = rand() % N;
        if (flag[index] == 0) {
            flag[index] = 1;
            chosen[count] = index;
            count++;
        }
    }
    printf("请输入输出文件名：");
    scanf("%s", filename);

    fout = fopen(filename, "w");
    if (!fout) {
        printf("无法创建文件 %s\n", filename);
        return 1;
    }
    printf("中奖名单如下：\n");
    fprintf(fout, "中奖名单如下：\n");
    for (i = 0; i < M; i++) {
        printf("%d. %s\n", i + 1, students[chosen[i]]);
        fprintf(fout, "%d. %s\n", i + 1, students[chosen[i]]);
    }

    fclose(fout);
    printf("结果已保存到文件 %s\n", filename);

    return 0;
}

7