实验5 结构体和文件

TASK 1-1

 

#include <stdio.h>
#define N 5
#define M 80
typedef struct
{
    char name[M];
    char author[M];    
 } Book;
 int main()
 {
     Book x[N] = { {"一九八四", "乔治.奥威尔"}, 
                  {"美丽新世界", "赫胥黎"},
                  {"昨日的世界", "斯蒂芬.茨威格"}, 
                  {"万历十五年", "黄仁宇"}, 
                  {"一只特立独行的猪", "王小波"}
                };
     
     int i;
    FILE *fp;
     
     fp = fopen("data1.txt", "w");
     
     if(fp == NULL) 
    { 
     printf("fail to open file\n"); 
     return 1; 
    }
     
     for(i=0; i<N; ++i) 
     { 
     fprintf(fp, "%-20s %-20s\n", x[i].name, x[i].author); 
     printf("%-20s %-20s\n", x[i].name, x[i].author); 
     }
     
     fclose(fp); 
     
     return 0;
 }

 

 

TASK 1-2

 

#include<stdio.h>
#define N 5
#define M 80

typedef struct
{
    char name[M];
    char author[M];
}Book;

int main()
{
    Book x[N];
    int i;
    
    FILE *fp;
    fp=fopen("data1.txt","r");
    if(fp==NULL)
    {
        printf("fail to open file\n");
        return 1;
    }
    
    for(i=0;i<N;++i)
    {
        fscanf(fp,"%s %s\n",x[i].name,x[i].author);
        printf("%-20s %-20s\n",x[i].name,x[i].author);
    }
    
    fclose(fp);
    
    return 0;
}

 

 

TASK 2

 

#include<stdio.h>
#define N 5
#define M 80
typedef struct
{
    char name[M];
    char author[M]; 
}Book;

int main()
{
    Book x[N] = { {"一九八四", "乔治.奥威尔"}, {"美丽新世界", "赫胥黎"}, {"昨日的世界", "斯蒂芬.茨威格"}, {"万历十五年", "黄仁宇"}, {"一只特立独行的猪", "王小波"} };
    
    int i;
    
    FILE *fp;
    
    fp=fopen("data2.dat","wb") ;
    
    if(fp==NULL)
    {
        printf("fail to open file\n");
        return 1;
    }
    
    fwrite(x,sizeof(Book),N,fp);
    
    fclose(fp);
    
    return 0;
     
}

 

生成且可见

 

TASK 2-2

 

#include<stdio.h>
#define N 5
#define M 80
typedef struct
{
    char name[M];
    char author[M]; 
}Book;

int main()
{
    Book x[N];
    int i;
    FILE *fp;
    fp=fopen("data2.dat","rb");
    if(fp==NULL)
    {
        printf("fail to open file\n");
        return 1;
    }
    
    fread(x,sizeof(Book),N,fp);
    
    for(i=0;i<N;++i)
    printf("%-20s%-20s\n",x[i].name,x[i].author);
    
    fclose(fp);
    return 0;
}

 

 

TASK 3-2

 

#include<stdio.h>

int main()
{
    FILE *fin;
    int c=0;
    char ch;
    fin=fopen("data3_1.txt","r");
    if(fin==NULL)
    {
        printf("fail to open data3_1.txt\n");
        return 1;
    }
    
    while(!feof(fin))
    {
        ch=fgetc(fin);
        if(ch!=' '&&ch!='\t'&&ch!='\n'&&ch!=EOF)
           ++c;    
    }
    
    fclose(fin);
    
    printf("data3_1.txt中共包含字符数：%d",c);
    
    return 0;
}

 

 

TASK 5

 

#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 a[N];
    float k;
    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)
            {
                a[0]=s[j];
                s[j]=s[j+1];
                s[j+1]=a[0];
            }
        }
        
     } 
     
    for(i=0;i<n;i++)
    {
        float p=1.0*i/n;
        int t;
        if(p<=0.1) t=1;
        else if(p>0.1&&p<0.5) t=2;
        else t=3;
        switch(t)
        {
            case 1: strcpy(s[i].level,"优秀");break;
            case 2: strcpy(s[i].level,"合格"); break;
            default:strcpy(s[i].level,"不合格");break;
        }
    }     
}

 

 

TASK 6

#include <stdio.h>
#include <stdlib.h>
#include <time.h>
#define N 81
#define M 5
typedef struct
{
   long int id; 
   char name[20];
   char class[60];
}STU;
int main()
{
    int i,j; 
    STU x[N],ran[M];
    FILE *fin,*fout;
    fin = fopen("list.txt","r");
    
    if(fin == NULL) 
    { 
       printf("fail to open list.txt\n"); 
       return 1;
    }
       
    for(i=1;i<=N;i++)
    {
       fscanf(fin, "%ld %s %s", &x[i].id, x[i].name, x[i].class); 
    }
    
    fclose(fin);
    
    srand(time(0));  
    j = rand()%(80)+1;  
    
    for(i=0;i<M;i++)
    {
        ran[i] = x[j];
        j = rand()%(80)+1;
    }
    
    fout = fopen("lucky.txt", "w"); 
    
    if(fout == NULL) 
    { 
       printf("fail to open file\n"); 
       return 1; 
    }
    
    for(i=0;i<M;i++) 
    {
       fprintf(fout, "%ld %s %s\n", ran[i].id, ran[i].name, ran[i].class); 
       printf("%ld %s %s\n", ran[i].id, ran[i].name, ran[i].class);
    }
    
    fclose(fout); 
    
    return 0;
}