实验七

实验四

代码

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

int main() {
    int line = 0;
    int chars = 0;
    char ch;
    char x;
    int y;

    FILE *fp;
    
    fp= fopen("data4.txt", "r");

    if (fp == NULL) 
    {
        printf("fail to open file to read\n");
        system("pause");
        return 1;
    }

    while ((ch = fgetc(fp)) != EOF) {
        y = 1;
        x = ch;

        if (ch == '\n') 
        {
            line++;
        } 
        else if (ch != ' ' && ch != '\t') 
        {
            chars++;
        }
    }

    if (y && x != '\n') 
    {
        line++;
    }

    printf("data4.txt统计结果:\n");
    printf("行数：%d\n", line);
    printf("字符数（不计算空白符）：%d\n", chars);

    fclose(fp);

    system("pause");
    return 0;
}

 

运行结果截图

 

实验五

代码

#include <stdio.h>
#include <stdlib.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: 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);

    system("pause");
    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("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);
}

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


// 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 st[], int n) 
{
    int i;

    FILE *fout = fopen("list_pass.txt", "w");

    if (!fout) 
    {
        printf("无法创建文件 list_pass.txt\n");
        return;
    }
    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结果\n");

    for (i = 0; i < n; i++) 
    {
        fprintf(fout, "%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);
    }
    fclose(fout);
}

 

运行结果截图

 

实验六（必做）

代码

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

#define m 80
#define w 5

typedef struct {
    char id[20];
    char name[20];
    char class_name[50];
} Student;

int main() {
    Student students[m];

    int count = 0;

    FILE *fp;

    int winner_indices[w];

    char filename[100];

    FILE *out;

    int i, j, x, y;

    size_t len;

    fp = fopen("list.txt", "r");

    if (fp == NULL) 
    {
        printf("fail to open file\n");
        return 1;
    }

    while (count < m &&fscanf(fp, "%s %s %[^\n]",students[count].id,students[count].name,students[count].class_name) == 3) 
    {
        count++;
    }
    fclose(fp);

    srand((unsigned int)time(NULL));

    for (i = 0; i < w; i++) 
    {
        do 
        {
            x = rand() % count;
            y = 0;
            for (j = 0; j < i; j++) 
            {
                if (winner_indices[j] == x) 
                {
                    y = 1;
                    break;
                }
            }
        } 
        while (y);

        winner_indices[i] = x;
    }
    printf("---中奖名单---\n");

    for (i = 0; i < w; i++) 
    {
        x = winner_indices[i];

        printf("%s    %s    %s\n",students[x].id,students[x].name,students[x].class_name);
    }
    printf("\n---保存到文件---\n");

    printf("输入文件名：");

    fflush(stdout);

    if (fgets(filename, sizeof(filename), stdin) != NULL) 
    {
        len = strlen(filename);

        if (len > 0 && filename[len - 1] == '\n') 
        {
            filename[len - 1] = '\0';
        }
    }

    out = fopen(filename, "w");

    if (out == NULL) 
    {
        printf("error %s\n", filename);
        return 1;
    }

    for (i = 0; i < w; i++) 
    {
        x = winner_indices[i];

        fprintf(out, "%s    %s    %s\n",students[x].id,students[x].name,students[x].class_name);
    }
    fclose(out);

    printf("保存成功！\n");

    system("pause");
    return 0;
}

 

运行结果截图