#include "iostream"
using namespace std;
#include "string"
using std::string;
#include <stdlib.h>

/*
Written By : Ahmad Jawed ZAFAR
Date : 11/02/2008
*/

double to_number(string str)
{
	if (str == "AA" || str == "aa")
	{
		return 4.0;
	}
	else if (str == "BA" || str == "ba")
	{
		return 3.5;
	}
	else if (str == "BB" || str == "bb")
	{
		return 3.0;
	}
	else if (str == "CB" || str == "cb")
	{
		return 2.5;
	}
	else if (str == "CC" || str == "cc")
	{
		return 2.0;
	}
	else if (str == "DC" || str == "dc")
	{
		return 1.5;
	}
	else if (str == "DD" || str == "dd")
	{
		return 1.0;
	}
	else if (str == "F" || str == "f" || str == "FF" || str == "ff")
	{
		return 0.0;
	}
	else
	{
		return -1;
	}
}

	class GPA
	{
	public:
		GPA() {total_credit=0; gpa=0; spa=0; total_mark=0;}
		~GPA() {}

	public:
		string subject[20];
		double credit[20];
		double total_credit;
		double total_mark;
		string letter_mark[20];
		double gpa;
		double spa;
	};

int main()
{
	int tot_sub;
	string select;

	GPA gpa1;

	cout << "Enter The Total Number of Subjects \n";
	cin >> tot_sub;

			for (int i=0; i<tot_sub; i++)
			{
				cout << "Enter The Subject : " << i+1 << "\n";
				cin >> gpa1.subject[i];
				cout << "\n";
				cout << "Credits For " << gpa1.subject[i] << " :> ";
				cin >> gpa1.credit[i];
				gpa1.total_credit += gpa1.credit[i];
				cout << "\n";
			}

			system("cls");

			do {

				for (int j=0; j<tot_sub; j++)
				{
					cout << "Enter The Letter Mark For " << gpa1.subject[j] << " :> ";
					cin >> gpa1.letter_mark[j];
					
					gpa1.total_mark += (double)(gpa1.credit[j] * to_number(gpa1.letter_mark[j]));
					cout << "\n";
				}

				cout << "Your GPA Is : " << (double)(gpa1.total_mark / gpa1.total_credit);
				cout << "\n\n";
				cout << "To Calculate Again Press 'A' To Exit Press 'X'\n";
				
				GPA();
				gpa1.total_mark=0;
				cin >> select;
				system("cls");
			} while (select != "x" || select != "X");

	system("pause");
	return 0;
}