task1-1

#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", "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); 
    return 0; 
}

 task1-2

#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; 
}

 task2-1

#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", "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("data2.dat", "wb"); 
    if(fp == NULL) 
    { 
        printf("fail to open file\n"); 
        return 1; 
    }
    fwrite(x, sizeof(Book), N, fp); 
    fclose(fp);
    return 0;
}

task2-2

#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; 
}

 task3-2

#include<stdio.h>
int main()
{
    FILE *fin;
    char ch;
    int i=0; 
    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!='\t'&&ch!='\n'&&ch!=' '&&ch!=EOF)
           i++; 
    }
    fclose(fin);
    printf("data3_1.txt中共包含字元數：%d",i);
    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; /*客觀題得分*/
    float subjective; /*操作題得分*/ 
    float sum; 
    char level[10]; 
} STU; // 函式宣告 
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); 
    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; // 輸出到螢幕 
    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); // 儲存到檔案 
    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,k;
    STU temp;
    for(i=0;i<n;i++)
        s[i].sum=s[i].objective+s[i].subjective;
    for(i=0;i<n;i++)
        for(k=0;k<n-1-i;k++)
            if(s[k].sum<s[k+1].sum)
            {
                temp=s[k];
                s[k]=s[k+1];
                s[k+1]=temp;
             }
    j=n/10;
    for(i=0;i<j;i++)
        strcpy(s[i].level,"優秀");
    k=n/2;
    for(i=j;i<k;i++)
        strcpy(s[i].level,"合格");
    for(i=k;i<n;i++)
        strcpy(s[i].level,"不合格"); 
    
 } 

 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 banji[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].banji); 
    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].banji); 
       printf("%ld %s %s\n", ran[i].id, ran[i].name, ran[i].banji);
    }
    fclose(fout); 
    return 0;
}