/*  Reads the grades of 10 students in 3 exams form an input file
    and prints the grades and average in a tabular form in another file
    also computes the overall average.

    Author:  Bashir Ghandi     Date: 18-09-1999        */


#include <stdio.h>

main()
{ long int id;
  int i;
  float ex1, ex2, ex3, avg, sum1=0,sum2=0,sum3=0;
  FILE *inp, *outp;
  char in_file[25];

  do
  {   printf ("Enter the name of input file >") ;
      scanf("%s", in_file);
      inp=fopen(in_file, "r");
      if (inp == NULL)
         printf ("Cannot open %s for input\n", in_file) ;
  } while (inp==NULL);

  outp=fopen("results.dat","w");
  fprintf(outp,"\nID\tEXAM1\tEXAM2\tEXAM3\tAVERAGE\n");
  for (i=1; i<=10; i++)
  {  fscanf(inp, "%ld%f%f%f",&id, &ex1, &ex2, &ex3);
     avg=(ex1+ex2+ex3)/3;
     fprintf(outp,"%ld\t%.2f\t%.2f\t%.2f\t%.2f\n", id,ex1,ex2,ex2,avg);
     sum1+=ex1;
     sum2+=ex2;
     sum3+=ex3;
  }      
  fprintf(outp,"AVERAGE\t %.2f\t%.2f\t%.2f\n",sum1/10, sum2/10, sum3/10);
  fprintf(outp, "OVERALL AVERAGE: %.2f\n",(sum1+sum2+sum3)/30); 
  fclose(inp);
  fclose(outp);
  return 0;
}