#include <stdio.h>
#include <stdlib.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", "喬治.奧威爾"},
                    {"美麗新世界", "赫胥黎"},
            
    {"昨日的世界", "斯蒂芬.茨威格"},
    
    {"萬曆十五年", "黃仁宇"},

    {"一隻特立獨行的豬
 
", "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);
    system(
 
"pause");
    return 0;
}

task1-2

#include <stdio.h>
#include <stdlib.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("%s %s\n",x[i].name,x[i].author);
    }
    fclose(fp);
    system("pause");
}

x[i].name本身就代表的是地址啊，所以不需要加取地址符

task2-1

#include <stdio.h>
#include <stdlib.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","喬治~奧威爾"},
    {"美麗新世界","赫胥黎"},
    {"昨日的世界","斯蒂芬~茨威格"},
    {"萬曆十五年","黃仁宇"},
    {"一隻特立獨行的貓","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);





system("pause");
}

確實生成了一個data2.dat

用word開啟可見

task2-2

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





system("pause");
}

task3-2

#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");
}

task 5

#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("從檔案讀入%d個考生資訊: 准考證號，姓名，客觀題得分(<=40)，操作題得分(<=60)\n", N);
    input(stu, N);
    printf("\n對考生資訊進行處理: 計算總分，確定等級\n");
    process(stu, N);
    printf("\n列印考生完整資訊, 並儲存到檔案中");

    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("准考證號\t姓名\t客觀題得分\t操作題得分\t總分\t\t等級\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, "准考證號\t\t姓名\t客觀題得分\t操作題得分\t總分\t\t等級\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,"優秀");}
    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

#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");
}