实验7

实验任务4

实验源代码

#include<stdio.h>

int main()
{
    //打开文件
     FILE *fp;
     int num = 0;
     if((fp = fopen("C:\\Users\\86150\\Desktop\\data4.txt","r"))==NULL)
    {
        printf("打开失败\n");
        return 0;
    }
    while(!feof(fp))
    {
      char x =  fgetc(fp);
      if(x != ' '&&x != '\n')
         {
         num++;}
         } 
    num = num - 1;
    printf("data4.txt中共包含字符数（不计空白字符）：%d",num);
    return 0;
 } 

运行结果

实验任务5

实验源代码

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

#define N 10

typedef struct {
    long int id;
    char name[20];
    float objective;    // 客观题得分
    float subjective;   // 操作题得分
    float sum;
    char level[10];
} STU;

// 函数声明
void input(STU s[], int n);
void output(STU s[], int n);
void process(STU s[], int n);

int main() {
    STU stu[N];

    printf("从文件读入%d个考生信息: 准考证号，姓名，客观题得分(<=40)，操作题得分(<=60)\n", N);
    input(stu, N);

    printf("\n对考生信息进行处理: 计算总分，确定等级\n");
    process(stu, N);

    printf("\n打印考生完整信息, 并保存到文件中");
    output(stu, N);

    return 0;
}

// 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 input(STU s[], int n) {
    int i;
    FILE *fin;

    fin = fopen("examinee.txt", "r");
    if (fin == NULL) {
        printf("fail to open file\n");
        exit(0);
    }

    while (!feof(fin)) {
        for (i = 0; i < n; i++)
            fscanf(fin, "%ld %s %f %f", &s[i].id, s[i].name, &s[i].objective, &s[i].subjective);
    }

    fclose(fin);
}

// 输出考生完整信息: 准考证号，姓名，客观题得分，操作题得分，总分，等级
// 不仅输出到屏幕上，还写到文本文件result.txt中
void output(STU s[], int n) {
    FILE *fout;
    int i;
    
    // 输出到屏幕
    printf("\n");
    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等级\n");
    for (i = 0; i < n; i++)
        printf("%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].level);
    
    // 保存到文件 
    fout = fopen("result.txt", "w");
    if (!fout) {
        printf("fail to open or create result.txt\n");
        exit(0);
    }
    
    fprintf(fout, "准考证号\t\t姓名\t客观题得分\t操作题得分\t总分\t\t等级\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", s[i].id, s[i].name, s[i].objective, s[i].subjective, s[i].sum, s[i].level);

    fclose(fout);
}

// 对考生信息进行处理：计算总分，排序，确定等级
void process(STU s[], int n) {
    int i,j;
    STU t;
    
    for(i = 0 ;i < n; i++)
        s[i].sum = s[i].objective + s[i].subjective;
    for(i = 0;i<n-1;i++)
        {
        for(j = 0; j<n-1-i;j++)
        {
          if(s[j].sum < s[j+1].sum)
          {
           t = s[j];
           s[j] = s[j+1];
           s[j+1] = t;}}}
    for(i = 0; i < n; i++)
        if(i == 0)
           strcpy(s[i].level , "优秀");
        else if( i > 0&&i <= 4)
           strcpy(s[i].level , "合格");
        else 
           strcpy(s[i].level , "不合格");
            
      
}

运行结果

实验任务6

实验源代码

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
 
#define N 80
#define M 5
 
typedef struct {
    int id;
    char name[50];
    char className[50];
} STU;
 
int main() {
    STU s[N];
    STU a[M];
    int i = 0;
 
    FILE *file = fopen("list.txt", "r");
    if (file == NULL) {
        printf("无法打开文件\n");
        return 0;
    }
 
    while (fscanf(file, "%d %s %[^\n]", &s[i].id, s[i].name, s[i].className) != EOF) {
        i++;
    }
 
    fclose(file);
 
    srand(time(NULL));
 
    int k;
    int index;
    int selected[N] = {0};
    for (k = 0; k < M; k++) {
        index = rand() % i;
        while (selected[index] == 1) {
            index = rand() % i;
        }
        selected[index] = 1;
        a[k] = s[index];
    }
 
    
    printf("学号\t姓名\t\t班级\n");
    for (i = 0; i < M; i++) {
        printf("%d\t%s\t\t%s\n", a[i].id, a[i].name, a[i].className);
    }
 
    FILE *outputFile = fopen("lucky.txt", "w");
    if (outputFile == NULL) {
        printf("无法创建文件\n");
        return 1;
    }
 
    fprintf(outputFile, "学号\t姓名\t\t班级\n");
    for (i = 0; i < M; i++) {
        fprintf(outputFile, "%d\t%s\t\t%s\n", a[i].id,a[i].name, a[i].className);
    }
 
    fclose(outputFile);
 
    return 0;
}

运行结果