实验7

任务四

源代码

#include <stdio.h>

int main() {
    FILE *fp;
    int ch;
    int lines = 0;
    int chars = 0;
	
	printf("data.txt统计结果：\n"); 
    fp = fopen("data4.txt", "r");

    while ((ch = fgetc(fp)) != EOF) {
        if (ch == '\n') {
            lines++;
        }
        if (ch != ' ' && ch != '\t' && ch != '\r' && ch != '\n') {
            chars++;
        }
    }

    fclose(fp);

    printf("行数：%d\n", lines);
    printf("字符数（不计空白符）：%d\n", chars);

    return 0;
}

运行结果截图

任务五

源代码

#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;

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;
}

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;
    }

    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);
}

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

void write(STU st[], int n) {
    FILE *fp;
    int i;

    fp = fopen("list_pass.txt", "w");
    if (fp == NULL) {
        printf("无法打开 list_pass.txt\n");
        return;
    }

    for (i = 0; i < n; i++) {
        fprintf(fp, "%ld %s %.2f %.2f %.2f %s\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

任务六

源代码

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

#define N 80

typedef struct {
    char id[15];
    char name[20];
    char cls[30];
} Student;

int main() {
    Student s[N], lucky[5];
    int flag[N] = {0};
    FILE *fp;
    int i, n = 0;
    int cnt = 0;
    char fname[50];

    fp = fopen("list.txt", "r");
    if (fp == NULL) {
        printf("无法打开 list.txt\n");
        return 1;
    }

    while (fscanf(fp, "%s%s%[^\n]", s[n].id, s[n].name, s[n].cls) != EOF) {
        n++;
    }
    fclose(fp);

    srand(time(NULL));

    while (cnt < 5) {
        int r = rand() % n;
        if (flag[r] == 0) {
            lucky[cnt] = s[r];
            flag[r] = 1;
            cnt++;
        }
    }

    printf("--- 中奖名单 ---\n");
    for (i = 0; i < 5; i++) {
        printf("%s %s %s\n", lucky[i].id, lucky[i].name, lucky[i].cls);
    }

    printf("保存到文件\n");
    printf("输入文件名：");
    scanf("%s", fname);

    fp = fopen(fname, "w");
    if (fp == NULL) {
        printf("文件保存失败\n");
        return 1;
    }

    for (i = 0; i < 5; i++) {
        fprintf(fp, "%s %s %s\n", lucky[i].id, lucky[i].name, lucky[i].cls);
    }
    fclose(fp);

    printf("保存成功！\n");
    return 0;
}

运行结果截图