实验5

task1.c
#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("datal.txt","w");
    if(fp==NULL)
    {
        printf("fail to open file\n");
        return 1;
     } 
    for(i=0;i<N;i++)
    {
        fprintf(fp,"%-20s %-21s\n",x[i].name,x[i].author);
        printf("%-21s %-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("datal.txt","r");
    if(fp==NULL)
    {
        printf("fail to open file\n");
        return 1;
     } 
    for(i=0;i<N;i++)
    {
        fprintf(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","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;
 }

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
#include<stdio.h>
int main()
{
    FILE *fin,*fout;
    char ch;
    fin=fopen("data3_1.txt","r");
    if(fin==NULL)
    {
        printf("fail to open data3_1.txt\n");
        return 1;
    }
    fout=fopen("data3_2.txt","w");
    if(fout==NULL)
    {
        printf("fail to open data3_2.txt\n");
        return 1;
    }
    while(!feof(fin))
    {
        ch=fgetc(fin);
        if(ch>='a'&&ch<='z')
        {
            ch-=32;
        }
        fputc(ch,fout);
    }
    fclose(fin);
    fclose(fout);
    return 0;
}

task5.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);

    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,k;
    float y, l;
    STU temp;
    for(i=0; i < n; i++)
        s[i].sum = s[i].objective + s[i].subjective;
    for (i = 1; i < n; i++)
        for (j = 0; j < i; j++) {
            if (s[i].sum > s[j].sum) {
                k = j;
                temp = s[i];
                for (j = i - 1; j >= k; j--)
                    s[j + 1] = s[j];
                s[k] = temp;
            }
        }
    y = s[(int)(n * 0.1 - 1)].sum;
    l = s[(int)(n * 0.5 - 1)].sum;
    for (i = 0; i < n; i++)
        if (s[i].sum >= y)
            strcpy(s[i].level, "优秀");
        else if (s[i].sum >= l)
            strcpy(s[i].level, "合格");
        else
            strcpy(s[i].level, "不合格");
}

task6.c
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>

#define N 80
#define M 5
typedef struct 
{
    char data[N];
    int flag;
} Stu;
int main() 
{
    struct tm *p;
    time_t lt;
    lt = time(NULL);
    p = localtime(&lt);
    char now1[30];
    strftime(now1, 30, "%Y%m%d.txt", p);

    int i, j, k;
    Stu s[N], l[M];
    FILE *fin, *fout;
    fin = fopen("list.txt", "r");
    if (fin == NULL) 
    {
        printf("fail to open file\n");
        return 0;
    }
    for (i = 0; i < N; i++) 
    {
        fgets(s[i].data, N, fin);
        printf("%s\n", s[i].data);
        s[i].flag = 0;
    }
    fclose(fin);

    for (j = 0; j < M; j++)   
    {
        i = 0;
        srand((unsigned)time(NULL));
        k = rand() % (N - j);
        while (k) 
        {
            if (s[i].flag == 0)
            k--;
            i++;
        }
        l[j] = s[i];
        s[i].flag = 1;
    }

    fout = fopen(now1, "w");
    if (fout == NULL) 
    {
        printf("fail to open file\n");
        return 0;
    }
    for (j = 0; j < M; j++) 
    {
        fprintf(fout, "%s\n", l[j].data);
    }
    fclose(fout);
    return 0;
}