实验七

实验结论

1.task4

• 代码

#define _CRT_SECURE_NO_WARNINGS
#include <stdio.h>

int main() {
    FILE* fp;
    int ch;
    int line_count = 0;
    int char_count = 0;
    int last_is_newline = 0; 

    // 打开data4.txt文件
    if ((fp = fopen("data4.txt", "r")) == NULL) {
        printf("fail");
        return 1;
    }

    while ((ch = fgetc(fp)) != EOF) {
        if (ch == '\n') {
            line_count++;
            last_is_newline = 1;
        }
        else {
            last_is_newline = 0;
        }

        if (ch > 32) {
            char_count++;
        }
    }

    if (last_is_newline == 0) {
        line_count++;
    }

    fclose(fp);

    printf("data4.txt统计结果:\n");
    printf("行数:\t\t %d\n", line_count);
    printf("字符数(不计空白符): %d\n", char_count);

    return 0;
}

• 运行结果截图
  
  2.task5
• 代码

#define _CRT_SECURE_NO_WARNINGS
#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: 已完成\n", N);
    read(stu, N);

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

    printf("\n所有考生完整信息:\n");
    output(stu, N);

    printf("\n通过考试的名单写入文件: 已完成!\n");
    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;
}

// 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;
    }

    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);
}

// 对考生信息进行处理：计算每位考生考试总分、结果；统计并返回通过考试的人数
int process(STU st[], int n, STU st_pass[]) {
    int i, 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[cnt] = st[i];
            cnt++;
        }
        else {
            strcpy(st[i].result, "未通过");
        }
    }
    
    return cnt;

}

// 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 st[], int n) {
    FILE* fp = fopen("list_pass.txt", "w");
    if (fp == NULL) {
        printf("fail");
        return;
    }
    fprintf(fp, "准考证号             姓名        客观题得分       操作题得分     总分     结果\n");
    for (int i = 0;i < n;i++) {
        fprintf(fp, "%-30ld%-10s%-10.2f%-10.2f%-10.2f%-10s\n", st[i].id, st[i].name, st[i].objective, st[i].subjective, st[i].sum, st[i].result);
       
    }
    fclose(fp);
}

• 运行结果截图
  

3.task6

• 代码（必）

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

#define MAX_STU 80
#define PICK_NUM 5

// 定义学生结构体
typedef struct {
    char id[20];
    char name[20];
    char className[30];
} Student;

// 1. 读取list.txt全部学生数据
int readStudent(Student stu[])
{
    FILE* fp = fopen("list.txt", "r");
    if (fp == NULL)
    {
        printf("无法打开list.txt文件\n");
        return 0;
    }
    int count = 0;
    // 循环读取每一行学生信息
    while (fscanf(fp, "%s %s %s", stu[count].id, stu[count].name, stu[count].className) == 3)
    {
        count++;
    }
    fclose(fp);
    return count;
}

// 2. 随机抽取指定数量不重复学生
void randomSelect(Student allStu[], int total, Student winStu[])
{
    int flag[MAX_STU] = { 0 }; // 标记数组：0未抽取，1已抽取
    int num = 0;
    srand((unsigned int)time(NULL)); // 设置随机种子，保证每次随机结果不同

    while (num < PICK_NUM)
    {
        int index = rand() % total; // 随机生成数组下标
        if (flag[index] == 0)
        {
            flag[index] = 1;
            winStu[num++] = allStu[index];
        }
    }
}

// 3. 将中奖名单写入自定义文件名的文件
void saveToFile(Student winStu[], char fileName[])
{
    FILE* fp = fopen(fileName, "w");
    if (fp == NULL)
    {
        printf("文件创建失败\n");
        return;
    }
    fprintf(fp, "========中奖名单========\n");
    for (int i = 0; i < PICK_NUM; i++)
    {
        fprintf(fp, "%s\t%s\t%s\n", winStu[i].id, winStu[i].name, winStu[i].className);
    }
    fclose(fp);
}

int main()
{
    Student allStudent[MAX_STU];
    Student winStudent[PICK_NUM];
    char saveFileName[50];
    int totalNum = readStudent(allStudent);

    if (totalNum == 0)
        return 1;

    // 随机抽奖
    randomSelect(allStudent, totalNum, winStudent);

    // 屏幕输出中奖名单
    printf("========中奖名单========\n");
    for (int i = 0; i < PICK_NUM; i++)
    {
        printf("%s\t%s\t%s\n", winStudent[i].id, winStudent[i].name, winStudent[i].className);
    }

    printf("\n输入文件名：");
    scanf("%s", saveFileName);
    strcat(saveFileName, ".txt");
    saveToFile(winStudent, saveFileName);
    printf("保存成功！\n");

    system("pause");
    return 0;
}

• 运行结果截图
  

• 代码（选）

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

#define MAX_STU 80
#define PICK_NUM 5

typedef struct {
    char id[20];
    char name[20];
    char className[30];
} Student;

int readStudent(Student stu[])
{
    FILE* fp = fopen("list.txt", "r");
    if (fp == NULL)
    {
        printf("无法打开list.txt文件\n");
        return 0;
    }
    int count = 0;
    while (fscanf(fp, "%s %s %s", stu[count].id, stu[count].name, stu[count].className) == 3)
    {
        count++;
    }
    fclose(fp);
    return count;
}

void randomSelect(Student allStu[], int total, Student winStu[])
{
    int flag[MAX_STU] = { 0 };
    int num = 0;
    srand((unsigned int)time(NULL));
    while (num < PICK_NUM)
    {
        int index = rand() % total;
        if (flag[index] == 0)
        {
            flag[index] = 1;
            winStu[num++] = allStu[index];
        }
    }
}

// 按学号字符串升序排列
void sortById(Student arr[], int n)
{
    for (int i = 0; i < n - 1; i++)
    {
        for (int j = 0; j < n - 1 - i; j++)
        {
            if (strcmp(arr[j].id, arr[j + 1].id) > 0)
            {
                Student temp = arr[j];
                arr[j] = arr[j + 1];
                arr[j + 1] = temp;
            }
        }
    }
}

// 获取系统日期作为文件名
void getDateFileName(char fileName[])
{
    time_t now = time(NULL);
    struct tm* t = localtime(&now);
    strftime(fileName, 50, "%Y%m%d.txt", t);
}

void saveToFile(Student winStu[], char fileName[])
{
    FILE* fp = fopen(fileName, "w");
    if (fp == NULL)
    {
        printf("文件创建失败\n");
        return;
    }
    fprintf(fp, "========%s中奖名单========\n", fileName);
    for (int i = 0; i < PICK_NUM; i++)
    {
        fprintf(fp, "%s\t%s\t%s\n", winStu[i].id, winStu[i].name, winStu[i].className);
    }
    fclose(fp);
}

int main()
{
    Student allStudent[MAX_STU];
    Student winStudent[PICK_NUM];
    char fileName[50];
    int totalNum = readStudent(allStudent);

    if (totalNum == 0)
        return 1;

    randomSelect(allStudent, totalNum, winStudent);
    sortById(winStudent, PICK_NUM); 

    // 屏幕打印排序后的中奖名单
    printf("========中奖名单（按学号升序）========\n");
    for (int i = 0; i < PICK_NUM; i++)
    {
        printf("%s\t%s\t%s\n", winStudent[i].id, winStudent[i].name, winStudent[i].className);
    }

    getDateFileName(fileName);
    saveToFile(winStudent, fileName);
    printf("\n文件自动保存为：%s，保存成功！\n", fileName);

    system("pause");
    return 0;
}

• 运行结果截图