实验七

实验4

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

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

   
    fp = fopen("data4.txt", "r");
    
    if (fp == NULL) {
        printf("文件打开失败！\n");
        return 1; 
    }

    while ((ch = fgetc(fp)) != EOF) {
        
        if (ch == '\n') {
            line_count++;
        }
        
        if (!isspace(ch)) {
            char_count++;
        }
    }

    
    if (char_count > 0) {
        line_count++;
    }

   
    fclose(fp);

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

    return 0;
}

 

实验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;
    }

    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 st[], int n) {
    int i;
    FILE *fout;

    fout = fopen("list_pass.txt", "w");

    if (!fout) {
        printf("fail to open write 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结果\n");

    for (i = 0; i < n; i++) {
        fprintf(fout, "%ld\t\t%s\t%.2f\t\t%.2f\t\t%.2f\t%s\n",
                st[i].id, st[i].name, st[i].objective, st[i].subjective, st[i].sum, st[i].result);
    }
    fclose(fout); 
}

int process(STU st[], int n, STU st_pass[]) {
    int i, pass_num = 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_num] = st[i];    
            pass_num++;                   
        } else {
            strcpy(st[i].result, "未通过"); 
        }
    }
    return pass_num; 
}

 

实验6

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

#define MAX_STU 80
#define SELECT_NUM 5

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

int read_stu(Student stu[], const char *filename) {
    FILE *fp = fopen(filename, "r");
    if (fp == NULL) {
        printf("无法打开文件 %s\n", filename);
        return -1;
    }

    int count = 0;
    while (count < MAX_STU && fscanf(fp, "%s %s %[^\n]", stu[count].id, stu[count].name, stu[count].cls) != EOF) {
        count++;
    }
    fclose(fp);
    return count;
}

int main() {
    Student stu_list[MAX_STU];
    int selected[SELECT_NUM] = {-1, -1, -1, -1, -1};
    int total_stu;
    char out_filename[50];
    FILE *fp;
    int i, rnd, flag;

    total_stu = read_stu(stu_list, "list.txt");
    if (total_stu < SELECT_NUM) {
        printf("学生数量不足，无法抽取%d人！\n", SELECT_NUM);
        return 1;
    }

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

    for (i = 0; i < SELECT_NUM; ) {
        rnd = rand() % total_stu;
        flag = 1;
        int j;
        for ( j = 0; j < i; j++) {
            if (selected[j] == rnd) {
                flag = 0;
                break;
            }
        }
        if (flag) {
            selected[i] = rnd;
            i++;
        }
    }

    printf("----------中奖名单----------\n");
    for (i = 0; i < SELECT_NUM; i++) {
        Student s = stu_list[selected[i]];
        printf("%s\t%s\t%s\n", s.id, s.name, s.cls);
    }
    printf("----------保存到文件----------\n");

    printf("输入文件名：");
    scanf("%s", out_filename);
    fp = fopen(out_filename, "w");
    if (fp == NULL) {
        printf("文件创建失败！\n");
        return 1;
    }
    for (i = 0; i < SELECT_NUM; i++) {
        Student s = stu_list[selected[i]];
        fprintf(fp, "%s\t%s\t%s\n", s.id, s.name, s.cls);
    }
    fclose(fp);
    printf("保存成功！\n");

    return 0;
}