实验7

实验任务4：

源代码：

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

int main() {
    FILE *fp;
    char line[100];
    int a = 0;
    int s = 0;
 9     int i;

    fp = fopen("data4.txt", "r");
    if (fp == NULL) {
        printf("fail to open file to write\n");
        return;
    }

    while (fgets(line, sizeof(line), fp)!= NULL) {
        a++;
19         int len = strlen(line);
        for (i = 0; i < len; i++) {
            if (line[i]!= '\n' && line[i]!= '\t' && line[i]!= ' ') {
                s++;
            }
        }
    }

    fclose(fp);

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

    return 0;
}

 试验任务5：

源代码：

 

#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 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);
    write(stu, N);

    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\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("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);
}

void write(STU s[], int n) {
    int i;
    FILE *fp;
    fp = fopen("list_pass.txt", "w");
    if (!fp) {
        printf("fail to open file\n");
        return;
    }
    for (i = 0; i < n; i++) {
        if (strcmp(s[i].result, "通过") == 0) {
            fprintf(fp, "%ld %s %.2f %.2f %.2f %s\n", s[i].id, s[i].name, s[i].objective, s[i].subjective, s[i].sum, s[i].result);
        }
    }
    fclose(fp);
}
    
int process(STU st[], int n, STU st_pass[]) {
    int count=0,i;
    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[count] = st[i];
            count++;
        } else {
            strcpy(st[i].result, "未通过");
        }
    }
    return count;
}

 

 

 

 试验任务6：

源代码：

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

#define M 80
#define N 5

typedef struct {
    char id[10];
    char name[20];
    char class[20];
} STU;

void read(STU student[]) {
    FILE *fp;
    int i;
    fp = fopen("list.txt", "r");
    if (fp == NULL) {
        printf("fail to open file to read\n");
        return;
    }
    for (i = 0; i < M; i++) {
        fscanf(fp, "%s %s %s", student[i].id, student[i].name, student[i].class);
    }
    fclose(fp);
}

void process(STU student[], STU select[], int n) {
    int x[M] = {0};
    int i;
    srand((unsigned int)time(NULL));
    for (i = 0; i < n; i++) {
        int a;
        do {
            a = rand() % M;
        } while (x[a] == 1);
        x[a] = 1;
        select[i] = student[a];
    }
}

void output(STU select[], int n) {
    printf("被抽中的学生信息：\n");
    int i;
    for (i = 0; i < n; i++) {
        printf("%-20s %-10s %-20s\n", select[i].id, select[i].name, select[i].class);
    }
}

void write(STU select[], int n) {
    FILE *fp;
    fp = fopen("20241222.txt", "w");
    if (fp == NULL) {
        printf("fail to open file to read\n");
        return;
    }
    int i;
    for (i = 0; i < n; i++) {
        fprintf(fp, "%s %s %s\n", select[i].id, select[i].name, select[i].class);
    }
    fclose(fp);
}

int main() {
    STU student[M];
    STU select[N];

    read(student);
    
    process(student, select, M);

    output(select, N);

    write(select, N);

    return 0;
}