实验7

任务4：

#include <stdio.h>
#define N 100
int main() {
    int i; 
    FILE *fp;
    int lines = 0;
    int chars = 0;

    fp = fopen("d:\\data4.txt", "r");
    if (!fp) {
        printf("fail to open file to read\n");
        return 1;
    }

    char str[N];
    while (fgets(str, N, fp)!= NULL) {
        lines++;
        for (i = 0; str[i]!= '\0'; i++) {
            if (str[i]!= ' ' && str[i]!= '\n') {
                chars++;
            }
        }
    }

    fclose(fp);
    printf("data4.txt统计结果：\n");
    printf("行数：%d\n", lines);
    printf("字符数(不计空白符)：%d\n", chars);

    return 0;
}

任务5：

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

#define N 10

typedef struct {
    long id;            // 准考证号
    char name[20];      // 姓名
    float objective;    // 客观题得分
    float subjective;   // 操作题得分
    float sum;          // 总分
    char result[10];    // 考试结果
} STU;

// 函数声明
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);   // 输出所有考生完整信息到屏幕
    write(stu, N);    // 输出考试通过的考生信息到文件

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

    return 0;
}

// 把所有考生完整信息输出到屏幕上
// 准考证号，姓名，客观题得分，操作题得分，总分，结果
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);
}

// 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 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);
}

// 把通过考试的考生完整信息写入文件list_pass.txt
// 准考证号，姓名，客观题得分，操作题得分，总分，结果
void write(STU s[], int n) {
    // 待补足
    int i;
    FILE *fout;
    fout = fopen("list_pass.txt", "w");
    if (!fout) {
        perror("fail to open file list_pass.txt");  // 使用perror输出更详细的错误信息
        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\t结果\n");
    for (i = 0; i < n; i++) {
        if (s[i].sum >= 60) {
            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);
}


// 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
int process(STU st[], int n, STU st_pass[]) {
    // 待补足
    int i, count = 0;
    for (i = 0; i < n; i++) {
        
        st[i].sum = st[i].objective + st[i].subjective;
        st[i].sum = (float)((int)(st[i].sum * 100 + 0.5)) / 100;

        if (st[i].sum >= 60) {
            strcpy(st[i].result, "通过");
            st_pass[count] = st[i];
            count++;
        } else {
            strcpy(st[i].result, "未通过");
        }
    }
    return count;
}

任务6：

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

#define NUM 80

typedef struct {
    int id;
    char name[20];
    char classes[20];
} Student;


void readStudents(Student students[]) {
    int i;
    FILE *fp;
    fp = fopen("d:\\list.txt", "r");
    if (fp == NULL) {
        perror("打开文件失败");
        exit(1);
    }
    for (i = 0; i < NUM; i++) {
        fscanf(fp, "%d %s %s", &students[i].id, students[i].name, students[i].classes);
    }
    fclose(fp);
}


void randomSelect(Student students[]) {
    int i;
    srand((unsigned int)time(NULL));
    int selected[5];
   
    for (i = 0; i < 5; i++) {
        int index;
        do {
            index = rand() % NUM;
        } while (index == selected[0] || index == selected[1] || index == selected[2] || index == selected[3] || index == selected[4]);
        selected[i] = index;
    }

    printf("随机随机点名名单\n");
    for (i = 0; i < 5; i++) {
        printf("%d %s %s\n", students[selected[i]].id, students[selected[i]].name, students[selected[i]].classes);
    }

    char filename[50];
    printf("请输入文件名：");
    scanf("%s", filename);
    FILE *fp;
    fp = fopen(filename, "w");
    if (fp == NULL) {
        perror("打开文件失败");
        exit(1);
    }
    for (i = 0; i < 5; i++) {
        fprintf(fp, "%d %s %s\n", students[selected[i]].id, students[selected[i]].name, students[selected[i]].classes);
    }
    fclose(fp);
    printf("保存成功！\n");
}

int main() {
    Student students[NUM];
    readStudents(students);
    randomSelect(students);
    return 0;
}