实验五

//task 1_1.c
//将图书信息写入文本data1.txt
#include<stdio.h>
#define N 5
#define M 80

typedef struct
{
    char name[M];  //书名
    char author[M];//作者 
}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;
   
   //以写的文本打开本文件data1.txt
   fp = fopen("data1.txt","w");
   
   //如果打开文件失败，输出提示信息并返回
   
   if(fp==NULL)
   {
       printf("fail to open file\n");
       return 1;
    } 
    
    //将结构体数组x中的图书信息写道fp指向的文件data1.txt
    //同时输出到屏幕
    
    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.c//
//从文本文件data.1.txt中读取图书信息，并打印输出屏幕 
#include<stdio.h>
#define N 5
#define M 80

typedef struct
{
    char name[M];  //书名
    char author[M];//作者 
}Book;
int main()
{
    Book x[N];
    int i;
    FILE *fp;
    //以只读的方式打开文本data.1.txt
    fp = fopen("data1.txt","r");
    
    //如果打开文件失败，输出提示信息并返回
    if(fp==NULL)
    {
        printf("fail to open file\n");
        return 1;
     } 

//从fp 指向的文件data.1.txt中读取信息到结构体数组x
//同时，把x的内容输出到屏幕上

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;
 } 
 

 

 

回答问题：x[i].name和x[i].author是数组，数组名已经是数组首地址，不能再加地址符。

//task 2_1.//
//将图书信息以数据块的方式写入二进制文件data2.dat
#include<stdio.h>
#define N 5
#define M 80

typedef struct
{
    char name[M];  //书名
    char author[M];//作者 
}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;
   //以写的方式打开 二进制文件data2.dat
   fp = fopen("data2.dat","wb");
   
   //如果打开文件失败，输出提示信息并返回
   if(fp==NULL)
   {
       printf("fail to open file\n");
       return 1;
    } 
    //将结构体数组x中的图书信息以数据块的方式写入文件
    //把从地址x处开始sizeof(Book)×N 个字节大小的数据写入fp指向的文件
    fwrite(x,sizeof(Book),N,fp);
    
    fclose(fp);
    return 0; 
}
 

 

 

//task.2_2.c//
//从二进制文件data.2.dat中读取图书信息，并打印输出屏幕 
#include<stdio.h>
#define N 5
#define M 80

typedef struct
{
    char name[M];  //书名
    char author[M];//作者 
}Book;
int main()
{
    Book x[N];
    int i;
    FILE *fp;
    //以读的方式打开文本data.2.dat
    fp = fopen("data2.dat","rb");
    
    //如果打开文件失败，输出提示信息并返回
    if(fp==NULL)
    {
        printf("fail to open file\n");
        return 1;
     } 
     
     //从指fo向的文件中读取数据块到x对应的地址单元 
     //数据块大小为sizeof(Book)×N 
     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_1.c//
//从文件data3.txt读取信息，将小写字母转换成大写后，写入data3_2.txt
#include<stdio.h>

int main()
{
    FILE *fin,*fout;
    char ch;
    
    //以只读、文本方式打开文件data3_1.txt
    fin = fopen("data3_1.txt","r");
    
     //如果打开文件失败，输出提示信息并返回
    if(fin==NULL)
    {
        printf("fail to open data3_1.txt\n");
        return 1;
     } 
     //以写、文本方式打开 文件data3_1.txt
     fout = fopen("data3_2.txt","w");
     
     //如果打开文件失败，输出提示信息并返回
    if(fout==NULL)
    {
        printf("fail to open data3_2.txt\n");
        return 1;
     } 
     
     //当fin指向的文件data3_1.txt没有结束时
     while( !feof(fin))
     {
         //从fin指向的文件 data3_1.txt中读取单个字符
         ch=fgetc(fin);
         
         //如果ch 是小写字母，转换成大写
         if(ch>='a'&&ch<='z')
         ch-=32;
         //将ch中的字符写入fout指向的 data3_2.txt
         fputc(ch,fout);
      } 
      fclose(fin);
      fclose(fout);
      return 0;
 } 

//task.3_2//
#include <stdlib.h>
#include <stdio.h>
int main()
{
    FILE *fin;
    char ch;
    long count=0;
    fin=fopen("data3_1.txt","r");

    if(fin==NULL)
    {
        printf("fail to open data3_1.txt\n");
        return 1;
    
    
    
    }


    while((ch=fgetc(fin))!=EOF)
        {
            if(ch!=' '&&ch!='    '&&ch!='\n')
            count++;}
    printf("%d",count);

    fclose(fin);




system("pause");
}

 

 

回答：生成task 3_2.txt,可见

//task.5.c//
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#define N 10
typedef struct
{
    long int id;
    char name[20];
    float objective;
    float subjective; 
    float sum;
    char level[10];
} STU;
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);
    system("pause");
    return 0;
}
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);
}
void output(STU s[], int n)
{
    FILE *fout;

    int i;
    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);

    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);
}
void process(STU s[], int n)
{
    int i,j,t;
    
    for(i=0;i<n;i++)
    {
        s[i].sum=(s[i].objective)+(s[i].subjective);
    }
    for(j=0;j<n;j++)
    {
        for(i=0;i<n-j;i++)
        {
            if(s[i].sum<s[i+1].sum)
            {
                t=s[i+1].sum;
                s[i+1].sum=s[i].sum;
                s[i].sum=t;}
        }    
    
    }

    for(i=0;i<1;i++)
    {
    strcpy(    s[i].level,"优秀");}
    for(;i>=1&&i<5;i++)
        strcpy(s[i].level,"合格");
    for(;i<n;i++)
        strcpy(s[i].level,"不合格");
}

 

 

//task.6.c//
#include<stdio.h>
#include<time.h>
#include<stdlib.h>
#define N 80
struct student
{
    char xuehao[11];
    char name[10];
    char grade[20];
};
int main()
{
    struct student std[N];   
    int i,t;
    FILE *fp,*fout;
    
    srand(time(0));
    
    fp=fopen("list.txt","r");
    if(fp==NULL)
    {
        printf("fail to open\n");
        exit(0);
    }
    fout=fopen("lucky.txt","w+");
 
    if(fout==NULL)
    {
        printf("fail to creat\n");
        exit(0);
    
    
    }
    for(i=0;i<N;i++)
    
        fscanf(fp,"%s %s %s",std[i].xuehao,std[i].name,std[i].grade);
    
    for(i=0;i<5;i++)
    {
        t=rand()%80;
   
        printf("%-20s %-20s %-20s\n",std[t].xuehao,std[t].name,std[t].grade);
        
        fprintf(fout,"%-20s %-20s %-20s\n",std[t].xuehao,std[t].name,std[t].grade);
            }
    
   
    fclose(fp);
    fclose(fout);
    system("pause");
}