实验7 文件应用编程

实验任务4

task4.c的源码，运行测试结果如下

#include <stdio.h>
#include <ctype.h>

int main() {
    FILE *file;
    char filename[] = "data4.txt";
    int line_count = 0;
    int char_count = 0;
    int ch;
    int in_line = 0; 

    file = fopen(filename, "r");
    if (file == NULL) {
        printf("无法打开文件 %s\n", filename);
        return 1;
    }

    while ((ch = fgetc(file)) != EOF) {
        if (ch == '\n') {
            line_count++;
            in_line = 0;
        } else if (!isspace(ch)) {
            char_count++;
            in_line = 1;
        }

    }


    if (in_line) {
        line_count++;
    }

    fclose(file);

    printf("%s统计结果：\n", filename);
    printf("行数：    %d\n", line_count);
    printf("字符数(不计空白符)：    %d\n", char_count);

    return 0;
}

 

 

实验任务5

task5.c的源码，运行测试结果如下

#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_pass, cnt);    // 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
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
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);
}

// 把通过考试的考生完整信息写入文件list_pass.txt
void write(STU s[], int n) {
    FILE *fout;
    int i;

    fout = fopen("list_pass.txt", "w");
    if (!fout) {
        printf("fail to create file\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\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);
}

// 对考生信息进行处理
int process(STU st[], int n, STU st_pass[]) {
    int i, pass_cnt = 0;
    
    for (i = 0; i < n; i++) {
        // 计算总分
        st[i].sum = st[i].objective + st[i].subjective;
        
        // 判断是否通过
        if (st[i].sum >= 60) {
            strcpy(st[i].result, "通过");
            // 将通过的考生信息复制到st_pass数组
            st_pass[pass_cnt] = st[i];
            pass_cnt++;
        } else {
            strcpy(st[i].result, "未通过");
        }
    }
    
    return pass_cnt;
}

 

实验任务6

task6.c的源码(含必做和选做部分），运行测试结果如下

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

#define TOTAL_STUDENTS 80
#define WINNERS 5

typedef struct {
    char id[10];        // 学号
    char name[20];      // 姓名
    char className[30]; // 班级名称
} Student;

void readStudents(Student students[], const char* filename);
void selectWinners(Student students[], Student winners[], int total, int winnersCount);
void displayWinners(Student winners[], int count);
void saveWinnersToFile(Student winners[], int count, const char* filename);
void generateDateFilename(char* filename);
void sortWinnersById(Student winners[], int count);

int main() {
    Student students[TOTAL_STUDENTS];
    Student winners[WINNERS];
    char filename[100];

    srand((unsigned int)time(NULL));

    readStudents(students, "list.txt");

    selectWinners(students, winners, TOTAL_STUDENTS, WINNERS);

    sortWinnersById(winners, WINNERS);

    printf("\n中奖名单：\n");
    displayWinners(winners, WINNERS);

    generateDateFilename(filename);
    saveWinnersToFile(winners, WINNERS, filename);

    printf("\n中奖名单已保存到 %s\n", filename);

    return 0;
}

void readStudents(Student students[], const char* filename) {
    FILE* file = fopen(filename, "r");
    if (file == NULL) {
        printf("无法打开文件 %s\n", filename);
        exit(1);
    }
    int i;
    for (i = 0; i < TOTAL_STUDENTS; i++) {
        fscanf(file, "%s %s %[^\n]", students[i].id, students[i].name, students[i].className);
    }

    fclose(file);
}

void selectWinners(Student students[], Student winners[], int total, int winnersCount) {
    int selected[TOTAL_STUDENTS] = {0};
    int count = 0;

    while (count < winnersCount) {
        int index = rand() % total;
        if (!selected[index]) {
            winners[count] = students[index];
            selected[index] = 1;
            count++;
        }
    }
}

void sortWinnersById(Student winners[], int count) {
    int i,j;
    for (i = 0; i < count - 1; i++) {
        for (j = 0; j < count - i - 1; j++) {
            if (strcmp(winners[j].id, winners[j + 1].id) > 0) {
                Student temp = winners[j];
                winners[j] = winners[j + 1];
                winners[j + 1] = temp;
            }
        }
    }
}


void displayWinners(Student winners[], int count) {
    printf("学号\t\t姓名\t\t班级\n");
    printf("----------------------------------------\n");
    int i;
    for (i = 0; i < count; i++) {
        printf("%s\t%s\t%s\n", winners[i].id, winners[i].name, winners[i].className);
    }
}

void generateDateFilename(char* filename) {
    time_t now;
    struct tm* timeinfo;
    time(&now);
    timeinfo = localtime(&now);
    
    strftime(filename, 20, "%Y%m%d.txt", timeinfo);
}

void saveWinnersToFile(Student winners[], int count, const char* filename) {
    FILE* file = fopen(filename, "w");
    if (file == NULL) {
        printf("无法创建文件 %s\n", filename);
        exit(1);
    }

    fprintf(file, "中奖名单：\n");
    fprintf(file, "学号\t\t姓名\t\t班级\n");
    fprintf(file, "----------------------------------------\n");
    int i;
    for (i = 0; i < count; i++) {
        fprintf(file, "%s\t%s\t%s\n", winners[i].id, winners[i].name, winners[i].className);
    }

    fclose(file);
}