#include <iostream.h>
#include <fstream.h>
#include "CPstring.h"

// file: gradefreq1.cc
// Author: D. Ramm;   Date: 10/27/96
// Collecting frequency data using if/else

// Assume grades represented by integers as follows:
//   A+  13     B+  10   C+  7    D+  4    F+  1
//   A   12     B    9   C   6    D   3    F   0
//   A-  11     B-   8   C-  5    D-  2
// Essentially an expansion of the 4 point scale.

int main()
{
   int ap = 0, a = 0, am = 0, bp = 0, b = 0, bm = 0;
   int cp = 0, c = 0, cm = 0, dp = 0, d = 0, dm = 0;
   int fp = 0, f = 0;
   string fname;
   int grade;

   cout << "enter file name: ";
   cin >> fname;

   ifstream data;
   data.open(fname);
   while ( data >> grade)
   {

      if (grade == 13)   ap++;
      else if (grade == 12) a++;
      else if (grade == 11) am++;
      else if (grade == 10) bp++;
      else if (grade == 9) b++;
      else if (grade == 8) bm++;
      else if (grade == 7) cp++;
      else if (grade == 6) c++;
      else if (grade == 5) cm++;
      else if (grade == 4) dp++;
      else if (grade == 3) d++;
      else if (grade == 2) dm++;
      else if (grade == 1) fp++;
      else if (grade == 0) f++;
   }

   cout << "Grade Distribution (A+ = 13, ..., F = 0)" << endl;
   cout << "13 " << ap << endl; cout << "12 " << a << endl;
   cout << "11 " << am << endl; cout << "10 " << bp << endl;
   cout << " 9 " << b << endl; cout << " 8 " << bm << endl;
   cout << " 7 " << cp << endl; cout << " 6 " << c << endl;
   cout << " 5 " << cm << endl; cout << " 4 " << dp << endl;
   cout << " 3 " << d << endl; cout << " 2 " << dm << endl;
   cout << " 1 " << fp << endl; cout << " 0 " << f << endl;
   return 0;
}

Sample output:

gradefreq1
enter file name: grades
Grade Distribution (A+ = 13, ..., F = 0)
13 3
12 4
11 6
10 7
 9 7
 8 4
 7 4
 6 3
 5 3
 4 2
 3 2
 2 2
 1 2
 0 3

cat grades
11 12 11 6 12 0 9 5 6 13 4 1 13
8 7 7 9 7 12 9 10 9 10 9 2 10
7 3 4 9 8 8 6 11 11 0 11 10 2
1 0 11 13 9 5 5 3 10 10 8 10 12