实验五

#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;
}

 

 

 

#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文件data1.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data1.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;
}

 

 

 

 它本身就是地址符，所以不需要加&

#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;


}

#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;
}

 

 可以

#include <stdio.h>
int main(){
    FILE *fin,*fout;
    char ch;
    int i=0;

    fin =fopen("data3_1.txt","r");
    if(fin==NULL){
        printf("fail to open file data3_1.txt\n");
        return 1;
    }
    
    fout =fopen("data3_2.txt","w");
    if(fout==NULL){
        printf("fail to open file data3_2.txt\n");
        return 1;
    }

    while(!feof(fin)){
        ch =fgetc(fin);
        if(ch>='a'&&ch<='z')
            ch-=32;
        
        if(ch>=33&&ch<=126)
            i+=1;
        fputc(ch,fout);
    }
    fclose(fin);
    fclose(fout);
    printf("共有字符数%d",i);
    return 0;
}

 

 

#include <stdio.h> 
#include <string.h> 
#include <stdlib.h>
#define N 10
typedef struct{
    long int id;
    char name[20];
    float ob;
    float sub;
    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].ob, &s[i].sub); 
    }
    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].ob, s[i].sub, 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].ob, s[i].sub, s[i].sum, s[i].level);

    fclose(fout);
}
void process(Stu s[],int n){
    int i,j,k;
    float you,liang;
    Stu temp;
    for(i=0;i<n;i++)
        s[i].sum=s[i].ob+s[i].sub;
    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;
            }
        }
    you=s[(int)(n*0.1-1)].sum;
    liang=s[(int)(n*0.5-1)].sum;
    for(i=0;i<n;i++)
        if(s[i].sum>=you)
            strcpy(s[i].level,"优秀");
        else if(s[i].sum>=liang)
            strcpy(s[i].level,"合格");
        else
            strcpy(s[i].level,"不合格");
}

 

 

#include <stdio.h> 
#include <stdlib.h>
#include<time.h>
#define N 80
#define M 5
typedef struct{
    char data[N];
    int flag;
}Stu;
int main(){
    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];
    }
    fout=fopen("result2.txt","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;

}