实验7

实验4：

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

int main() {
    FILE *fp;
    int sum = 0;
    char lines[100][1000]; 
    int i = 0, n;

    fp = fopen("C:\\Users\\legion\\Desktop\\实验7数据文件及部分代码\\data4.txt", "r");
    if (fp == NULL) {
        printf("fail to open file to read\n");
        return 0;
    }

    while (fgets(lines[i], sizeof(lines[i]), fp)!= NULL) 
        i++;
    
    n = i;

    for (int j = 0; j < n; j++) {
        int w = strlen(lines[j]);
        for (int m = 0; m < w; m++) {
            if (lines[j][m] ==' '||lines[j][m]=='\t'||lines[j][m]=='\n') 
                w--;
            
        }
        sum += w;
    }
    printf("data4.txt统计结果：\n");
    printf("行数：                %d\n", n);
    printf("字符数（不计空白符）：%d\n", sum);

    fclose(fp); 

    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("C:\\Users\\legion\\Desktop\\实验7数据文件及部分代码\\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);
}

// 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 s[], int n) {
    int i;
    FILE *fp;
    
    fp = fopen("C:\\Users\\legion\\Desktop\\实验7数据文件及部分代码\\list_pass.txt","w");
    if(fp == NULL){
        printf("fail to open file to write\n");
        return ;
    }
    for(i=0;i<n;i++){
        fprintf(fp,"%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(fp);
}

// 对考生信息进行处理：计算每位考生考试总分、结果；统计考试通过的人数
int process(STU st[], int n, STU st_pass[]) {
   int i;
   int j=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[j++]=st[i];
       }
    else
           strcpy(st[i].result,"不通过");
   }
   return j;
}

 

实验6：

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

#define STUDENT_NUM 80

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

void swap(Student *a, Student *b) {
    Student temp = *a;
    *a = *b;
    *b = temp;
}

void random(Student students[], int n, Student selected[], int m) {
    srand((unsigned int)time(NULL));
    int i, j;
    for (i = 0; i < n; i++) {
        j = rand() % (n - i) + i;
        swap(&students[i], &students[j]);
    }
    for (i = 0; i < m; i++) 
        selected[i] = students[i];
    
}

void output(Student students[], int n) {
    int i;
    for (i = 0; i < n; i++) 
        printf("%d  %s  %s\n", students[i].id, students[i].name, students[i].class);
}


void write(Student students[], int n, char *filename) {
    FILE *fp;
    int i;
    fp = fopen(filename, "w");
    if (fp == NULL) {
        printf("无法打开文件\n");
        return;
    }
    for (i = 0; i < n; i++) 
        fprintf(fp, "%d %s %s\n", students[i].id, students[i].name, students[i].class);
    printf("保存成功！\n");
    fclose(fp);
}

int main() {
    Student students[STUDENT_NUM];
    Student selected[5];
    char filename[100];
    int i;
    
    for (i = 0; i < STUDENT_NUM; i++) {
        students[i].id = 204942000 + i;
        sprintf(students[i].name,  "学生%d", i + 1);
        sprintf(students[i].class,  "星际联盟2049(1)班");
    }
    random(students, STUDENT_NUM, selected, 5);
    printf("---------随机抽取名单-----------：\n");
    output(selected, 5);
    printf("---------保存到文件-----------：\n");
    printf("请输入文件名：");
    scanf("%s", filename);
    write(selected, 5, filename);
    return 0;
}