实验七

实验任务4：

1.源代码：

#define _CRT_SECURE_NO_WARNINGS
#include <stdio.h>

int main() 
{
    FILE* fp;
    char ch;
    int line = 0;
    int charcount = 0;
    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++;
        }
        else if (ch != ' ' && ch != '\t')
        {
            charcount++;
        }
    }
    if (charcount > 0)
        line++;
    fclose(fp);
    printf("data4.txt统计结果：\n");
    printf("行数：                %d\n", line);
    printf("字符数（不计空白符）：%d\n", charcount);
}

2.运行效果截图：

 

实验任务5：

1.源代码：

#define _CRT_SECURE_NO_WARNINGS
#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: 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;
    int pass_cnt = 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_cnt] = st[i];
            pass_cnt++; 
        }
        else
        {
            strcpy(st[i].result, "未通过");
        }
    }
    return pass_cnt;
}

void write(STU st[], int n) 
{
    FILE* fp = fopen("list_pass.txt", "w");
    if (fp == NULL)
    {
        printf("文件打开失败！\n");
        return ;
    }
    int i;
    fprintf(fp, "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(fp, "%ld\t%s\t%.2f\t%.2f\t%.2f\t%s\n",
            st[i].id, st[i].name,
            st[i].objective, st[i].subjective,
            st[i].sum, st[i].result);
    }
    fclose(fp);
}

2.运行效果截图

 

实验任务6：

1.源代码：

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

#define N 80
#define M 5

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

int main()
{
    Student stu[N];
    int total = 0;
    int flag[N] = { 0 }; 
    Student win[M];
    char filename[50];

    FILE* fp = fopen("C:\\Users\\Lenovo\\Desktop\\实验7数据文件及部分代码_gbk\\list.txt", "r");
    if (fp == NULL)
    {
        printf("无法打开list.txt\n");
        return 1;
    }
    while (fscanf(fp, "%ld %s %[^\n]", &stu[total].id, stu[total].name, stu[total].cls) == 3)
    {
        total++;
    }
    fclose(fp);

    srand((unsigned)time(NULL));
    int cnt = 0;
    while (cnt < M)
    {
        int r = rand() % total;
        if (flag[r] == 0)
        {
            flag[r] = 1;
            win[cnt++] = stu[r];
        }
    }

    printf("=====中奖名单=====\n");
    for (int i = 0; i < M; i++)
    {
        printf("%ld %s %s\n", win[i].id, win[i].name, win[i].cls);
    }

    printf("输入保存文件名：");
    scanf("%s", filename);
    FILE* fw = fopen(filename, "w");
    if (fw == NULL)
    {
        printf("文件创建失败\n");
        return 1;
    }
    for (int i = 0; i < M; i++)
    {
        fprintf(fw, "%ld %s %s\n", win[i].id, win[i].name, win[i].cls);
    }
    fclose(fw);
    printf("保存成功！\n");

    system("pause");
    return 0;
}

2.运行效果截图：