/* Loops   while( condition ) {  statements   }

                                   file: 3ex1.cpp  (or used as 3ex1.appended)
   FALL 1998
   ___________________________________
   Jacob Y. Kazakia   jyk0
   September 12, 1998
   Programming example  1 of unit #3
   Recitation Instructor: J.Y.Kazakia
   Recitation Section  01
   ___________________________________

   Purpose: This program reads a sequence of  test scores a, b, c, etc....
            and calculates the average of them.  The sequence is terminated
            when -1 is inserted as a test score.
            The scores entered as well as the average are outputted to a file
            called 3ex1report.txt with an appropriate heading.


   Algorithm: The score entered is stored in the variable  float score.
              Then the variable sum  ( which is float and initialized at
              the begining to zero ) is increased by the score:

              sum = sum + score    or equivalently   sum += score

              As the scores are entered an integer named count is increased
              so that the number of entries is registered.

              Finally we calculate   average = sum / count   and it is outputted.
                                                                          */

#include<iostream.h>         // header which contains the functions
                             // needed for default input and output

#include<fstream.h>          // header needed for file input output


void main()
{
ofstream report ( "3ex1report.txt", ios :: out);

float score ;    // the test score entered
float sum = 0;
float average;  // the average score

int count = 0;  // counter of scores entered . It starts as zero,
                // ends as the total number of scores.

cout<<" \n\n  Enter the first score  (-1 to terminate)   " ;
cin >> score;
 
report << "\n\n This is the list of scores entered \n\n";

 
while ( score >= 0)             // read the scores and add them up
  {
   count = count + 1;
   report << " score # " << count << "  is  " << score << endl;
   sum = sum + score;

   cout << "  \n Enter  the next score ( -1 terminates)   " ;

   cin >> score;

   }

 
if ( count > 0 )
   {
     average = sum / count;
     report << " \n\n number of scores entered : "<< count ;
     report << ". The average score is  "<< average ;
   }

cout << " \n \n  Done! " ;

cout << " \n\n  Enter e(exit) to exit    ...";
char hold;
cin >> hold;

}

/*

    THIS IS THE OUTPUT TO THE DEFAULT WINDOW:

  Enter the first score  (-1 to terminate)   97

 Enter  the next score ( -1 terminates)   83

 Enter  the next score ( -1 terminates)   76

 Enter  the next score ( -1 terminates)   95

 Enter  the next score ( -1 terminates)   88

 Enter  the next score ( -1 terminates)   34

 Enter  the next score ( -1 terminates)   56

 Enter  the next score ( -1 terminates)   -1


  Done!

  Enter e(exit) to exit    ...


  THE CORRESPONDING FILE IS :

      

  This is the list of scores entered

 score # 1  is  97
 score # 2  is  83
 score # 3  is  76
 score # 4  is  95
 score # 5  is  88
 score # 6  is  34
 score # 7  is  56
 
 
 number of scores entered : 7. The average score is  75.5714

 */