wu

#include<stdio.h>

struct student

{

int id;

char name[20];

float score[3];

};

int main()

{

FILE *fp;

if((fp = fopen("D:\\student.xtx","rw"))==NULL)

{

printf("cannot open file!\n");

return 0;

}

struct student s[5];

for(int i=0;i<5;i++)

{

scanf("%d%s%f%f%f",&s[i].id,s[i].name,&s[i].score[0],&s[i].score[1],&s[i].score[2]);

}

int a=0;

float avg[3],sum[3];

for(int i=0;i<3;i++)

{

sum[i]+=s[i].score[0]+s[i].score[1]+s[i].score[2];

avg[i]=sum[i]/3;

}

for(int i=0;i<5;i++)

{

fputc(s[i].id,fp);

}

fputc(avg[0],fp);

fputc(avg[1],fp);

fputc(avg[2],fp);

fclose(fp);

return 0;

}