实验七

任务4：

#include <stdio.h>
#include <ctype.h>
#define N 100
int main(){
    char ch;
    FILE *fp;
    int lines=0;
    int chars=0;

    fp = fopen("d:\\data4.txt", "r");
    if(!fp) {
        printf("fail to open file to read\n");
        return 1;
    }

    char str[N];
    while(!feof(fp)){
        fgets(str,101,fp);
        lines++;
        int i=0;
        while(str[i]!='\0'){
            if(str[i] != ' ' && str[i] != '\n')
                chars++;
            i++;
        }
    }
   

    fclose(fp);
    printf("data4.txt统计结果：\n");
    printf("行数：%d\n", lines);
    printf("字符数(不计空白符)：%d\n", chars);
}

任务5：

#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("d:\\examinee.txt", "r");
    if (!fin) {
        printf("fail to open file\n");
        return 1;
    }

    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 *fout;
    fout = fopen("list_pass.txt","w");
     if (!fout) {
        printf("fail to open file\n");
        return 1;
    }
    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++) {
        if (s[i].sum >= 60) {
            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);
}

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

任务6：

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

#define NUM 80

typedef struct {
    int id;
    char name[20];
    char classes[20];
} Student;


void readStudents(Student students[]) {
    FILE *fp;
    fp = fopen("d:\\list.txt", "r");
    if (fp == NULL) {
        perror("打开文件失败");
        exit(1);
    }
    for (int i = 0; i < NUM; i++) {
        fscanf(fp, "%d %s %s", &students[i].id, students[i].name, students[i].classes);
    }
    fclose(fp);
}


void randomSelect(Student students[]) {
    srand((unsigned int)time(NULL));
    int selected[5];
   
    for (int i = 0; i < 5; i++) {
        int index;
        do {
            index = rand() % NUM;
        } while (index == selected[0] || index == selected[1] || index == selected[2] || index == selected[3] || index == selected[4]);
        selected[i] = index;
    }

    printf("随机随机点名名单\n");
    for (int i = 0; i < 5; i++) {
        printf("%d %s %s\n", students[selected[i]].id, students[selected[i]].name, students[selected[i]].classes);
    }

    char filename[50];
    printf("请输入文件名：");
    scanf("%s", filename);
    FILE *fp;
    fp = fopen(filename, "w");
    if (fp == NULL) {
        perror("打开文件失败");
        exit(1);
    }
    for (int i = 0; i < 5; i++) {
        fprintf(fp, "%d %s %s\n", students[selected[i]].id, students[selected[i]].name, students[selected[i]].classes);
    }
    fclose(fp);
    printf("保存成功！\n");
}

int main() {
    Student students[NUM];
    readStudents(students);
    randomSelect(students);
    return 0;
}