/*********************************************************************

  Filename:  studentrecord.cpp
  
  Program Description:

* This program gets student information from previous and current quarters.It
* then calculates and displays the new cumulative GPA, current GPA,
* total credits, and student ID .


*********************************************************************/


#include <iostream.h> // cin, cout
#include <iomanip.h> // setprecision(), setiosflags()

void getInput(char [], int,int &, float &, int &,int &,float & );
void doCalculations(int &, float &, int &, float &, float &, int &, float &);
void displayOutput(char [], int, float, float);

float calculateGPA(int, int);
float calculateTotalGPA(float, int, float, int);
int calculatetotalcredits(int,int);



/*******************************************************************************
* Function: main()
* Description: Gets student information from the keyboard, performs calculations
* on it, then prints it to the screen.
* Inputs: Reads input from the keyboard.
* Outputs: Writes output to the screen.
* Preconditions: <None>
* Postconditions: Prints to the screen and takes input from the keyboard.
*******************************************************************************/
void main(void)
{
const int studentIDLength = 10;      // Length of studentID[]
char studentID[studentIDLength];    // Student ID#
int previousCredits;                 // Number of credits previously
int previouscoursegrades;         // Number of previous grade points
float currentGradePoints;             // Number of honor points this quarter                                                          // completed
float previousGPA;                  // Previous GPA
int currentCredits;                  // Number of credits this quarter
int currentcourses;                  // Number of courses taken this quarter
float currentGPA;                    // GPA for this quarter
int totalCredits;                    // Total credit units
float totalGPA;                     // Overall GPA

//
// Get input from user.
//
getInput(studentID, studentIDLength, previousGPA,
previousCredits, currentcourses, previouscoursegrades);



//
// Perform calculations.
//
doCalculations(currentGPA, totalGPA, totalCredits);

//
// Output results.
//
displayOutput(studentID, currentGPA, totalGPA, totalCredits);
}


/*******************************************************************************
* Function: getInput()
* Description: Prompts for input and takes input for eight variables
* Inputs: All input is taken from the keyboard
* Outputs: All prompts are output to the screen
* Preconditions: studentID entered from keyboard must be no longer than
* studentIDLength - 1. studentName entered from keyboard must be
* no longer than studentNameLength - 1. Only integer
* numbers must be entered where integers are expected. Only
* floating point numbers must be entered where floating point
* numbers are expected.
* Postconditions: Output is displayed on screen. studentID{},
* currentGPA,totalCredits, totalGPA. 
* variables are modified.
*******************************************************************************/
void getInput(/* Out */ char studentID[],      // Student ID#
/* In */ int studentIDLength,                  // Length of studentID[]
/* Out */ int &previousCredits,                // Number of credits previously
/* Out */ float &previousGPA,                  // Previous GPA
/* Out */ int &previouscoursegrades,           // Number of previous honor points  
/* Out */ int &currentCredits,                // Number of credits this quarter
/* Out */ int &currentcourses,               // Number of courses taken this quarter
/* Out */ float &currentGradePoints);          // Number of grade points
    
{
                                                                              
{
int previouscredits; // Number of credits from input
int previouscoursegrades; // Number of grade points from input

currentCredits = 0;
currentGradePoints = 0;
currentcourses= 0;

//
// Prompt for input and get input from keyboard.
//
cout << "Student ID#: ";
cin.getline(studentID, studentIDLength);

cout << "Previous GPA: ";
cin >> previousGPA;

cout << "Previous number of credits: ";
cin >> previousCredits;

cout << "Previous Grade Points: ";
cin >> previouscoursegrades;

cout << "Previous Grade Points: ";
cin >> currentCredits;

cout << "Number of couses taken: ";
cin >> currentcourses;


//
// Get credit unit values and grades from one line of input from keyboard.
//
cout << "Credit unit values and grades: ";
for(int i = 0; i < currentCourses; i++)
        {
                cin >> previouscredits;
                cin >> previouscoursegrades;

                currentCredits += previouscredits;
                currentGradePoints += previouscoursegades* credits;
        }
}


/*******************************************************************************
* Function: doCalculations()
* Description: Performs the calculations and returns the results through the
* parameters.
* Preconditions: <None>
* Postconditions: Changes currentGPA, totalCredits and totalGPA.
*******************************************************************************/
void doCalculations(
                                                                                                
/* In */ int &previousCredits,                // Number of credits
/* In */ float &previousGPA,                  // Previous GPA
/* In */ int &currentCredits,                 // Current credits 
/* In */ float &currentGradePoints,           // Number of grade
/* Out */ float &currentGPA,                 // GPA for this quarter
/* Out */ int &totalCredits,                 // Total credit units
/* Out */ float &totalGPA,                   // Overall GPA
                                                                                                // quarter
{

	
currentGPA = calculateGPA(currentGradePoints, currentCredits);

totalCredits = calculatetotalcredits(previousCredits, currentCredits);

totalGPA = calculateTotalGPA(previousGPA, previousCredits, currentGradePoints,
totalCredits);



}


/*******************************************************************************
* Function: calculateGPA()
* Description: Given a the number of grade points and credits, this function
* calculates and returns the GPA.
* Preconditions: credits must not be zero.
* Postconditions: Returns the resulting GPA.
*******************************************************************************/
float calculateGPA(/* In */ float currentGradePoints,      // Number of grade points
/* In */ int currentcredits)                                                     // Number of credits
{
float GPA; // Grade Point Average

GPA = currentGradePoints / currentcredits;

return GPA;
}


/*******************************************************************************
* Function: calculateTotalGPA()
* Description: Given the previous quarter's GPA, the previous quarter's
* credits, the current quarter's grade points and the total
* credits earned overall, this function calculates and returns
* the overall GPA.
* Preconditions: totalCredits must not be zero.
* Postconditions: Returns the resulting overall GPA.
*******************************************************************************/
float calculateTotalGPA(/* In */ float previousGPA,      // Previous GPA
/* In */ int previousCredits,                            // Number of credits
                                                                                                  // previously
                                                                                                  // completed
/* In */ float currentGradePoints,                       // Number of grade
                                                                                                  // points this
                                                                                                  // quarter
/* In */ int totalCredits)                                  // Total credits for all
                                                                                                 // quarters
{
float totalGPA; // Overal GPA for all quarters

//
// Calculate overall GPA.
//
totalGPA = (previousGPA * previousCredits + currentGradePoints) / totalCredits;

return totalGPA;
}




/*******************************************************************************
* Function: displayOutput()
* Description: Prints the results of the calculations to the screen.
* Outputs: Prints all output to the screen.
* Preconditions: <None>
* Postconditions: Output is printed to the scree.
*******************************************************************************/
void displayOutput
(/* In */ char studentID[],               // Student ID#

/* In */ int totalCredits,            // Total credits completed
/* In */ float totalGPA,              // Overall GPA
/* In */ float currentGPA,            // GPA for this quarter
{

//
// Print results to screen.
//
cout << "Student ID#: " << studentID << endl;
cout << "Total number of credit units: " << totalCredits << endl;
cout << "Cumulative GPA: " << setprecision(2)
        << setiosflags(ios::fixed | ios::showpoint) << totalGPA << endl;
cout << "GPA for the current quarter: " << setprecision(2)
        << setiosflags(ios::fixed | ios::showpoint) << currentGPA << endl;


}
return 0;

void doCalculations( int    &previousCredits,    // Number of credits
                     float &previousGPA,         // Previous GPA
                     int   &currentCredits,      // Current credits 
                     float &currentGradePoints,  // Number of grade
                     float &currentGPA,          // GPA for this quarter
                     int   &totalCredits,        // Total credit units
                     float &totalGPA,            // Overall GPA
                       //Are there more?                                                                          // quarter
{

  void doCalculations(int &, float &, int &, float &, float &, int &, float &);

  doCalculations(currentGPA, totalGPA, totalCredits);