CSC133 Intro to CS in C++: Topdown Development

Sample Program: Topdown Development

Problem Statement

Write a program that will process semester grades and print a grade report for each student.

For each student the input will be:

student ID and number of courses
course number, number of credits, grade (one line like this for each course)

For each student the output will be:

heading ‘Grade Report’
student id
course number, number of credits, grade (one line like this for each course)
total credits, gpa

Calculations:

calculate the total number of credits for all courses
calculate the grade points for each course (grade points = number of credits * grade)
calculate the total number of grade points for all courses
gpa = total number of grade points / total number of credits

Pseudocode

main:

get student id and number of courses
while there are more students
{
   print heading on grade report
   calculate GPA
   print grade report
   get student id and number of courses
}

calculate gpa:

for each course
{
   get course number, credits, grade
   grade points = grade points + credits * grade
   total credits = total credits + credits
}
gpa = grade points / total credits

print grade report:

How can we print the course number, credits and grade for each course now? We don’t have all of them anymore - we only have the values for the last course.

Pseudocode: Second Try

main:

get student id and number of courses
while there are more students
{
   print heading on grade report
   total credits = 0
   grade points = 0
   process courses
   calculate and print GPA
   get student id and number of courses
}

process courses:

for each course
{
   get course number, number of credits, grade
   print course number, number of credits, grade
   grade points = grade points + credits * grade
   total credits = total credits + credits
}

calculate and print gpa:

gpa = grade points / total credits
print a blank line
print total credits, gpa

Code:

//  process student grade data and print grade report for each
//  student read data from file student.dat. for each student, print
//  course data, then calculate and print gpa

#include 
#include 
#include 

void heading(long);
void processCourses(ifstream&, int, int&, float&);
void calcAndPrintGpa(int,float);

int main()
{
   long studentid;
   int numcourses;
   int totalcredits;
   float gradepoints;
   ifstream students;

//  set up output to print float values
   cout << setiosflags(ios::fixed);
   cout << setiosflags(ios::showpoint);
   students.open("student.dat");

//  each iteration of the loop processes one student
   students >> studentid >> numcourses;
   while (students)
   {
      heading(studentid);
      totalcredits = 0;
      gradepoints = 0;
//  set output to one decimal place for printing course grades,
//  then call func to read course info, print it, and calc total
//  credits and total gradepoints
      cout << setprecision(1);
      processCourses(students,numcourses,totalcredits,gradepoints);
//  set output to three decimal places for printing gpa, then call
//  func to calc and print the gpa
      cout << setprecision(3);
      calcAndPrintGpa(totalcredits,gradepoints);
      students >> studentid >> numcourses;
   }
}

//  create heading for a student's grade report
void heading(long studentid)
{
   cout << "*************************************************\n\n";
   cout << "                 Grade Report\n\n";
   cout << "   Student:   " << studentid << endl << endl;
   cout << "   Course\n";
   cout << "   Number                 Credits            Grade\n\n";
}

//  loop through all courses for a given student: read course number,
//  credits, and grade, print them, and calc total credits and
//  gradepoints (gradepoints for a course are credits * grade)
void processCourses(ifstream& students, int numcourses,
                    int& totalcredits, float & gradepoints)
{
   int i;
   float grade;
   int credits;
   int coursenum;

   for (i = 1 ; i <= numcourses ; i++)
   {
      students >> coursenum >> credits >> grade;
      cout << setw(7) << coursenum << setw(22) << credits
           << setw(20) << grade << endl;
      totalcredits = totalcredits + credits;
      gradepoints = gradepoints + credits * grade;
   }
}

//  calc gpa and print total credits and gpa
void calcAndPrintGpa(int totalcredits, float gradepoints)
{
   float gpa;
   gpa = gradepoints / totalcredits;
   cout << "\nTotal credits:" << setw(10) << totalcredits;
   cout << endl << endl;
   cout << "GPA:" << setw(13) << gpa << endl << endl;
}

Input File student.dat

Output

*************************************************

                 Grade Report

   Student:   11223344

   Course
   Number                 Credits            Grade

    133                     4                 3.5
    129                     4                 3.0
    121                     3                 4.0

Total credits:        11

GPA:        3.455

*************************************************

                 Grade Report

   Student:   88887777

   Course
   Number                 Credits            Grade

    133                     4                 4.0
    121                     3                 3.5

Total credits:         7

GPA:        3.786

*************************************************

                 Grade Report

   Student:   99775533

   Course
   Number                 Credits            Grade

    133                     4                 3.0
    125                     3                 2.0
    121                     3                 2.5

Total credits:        10

GPA:        2.550