// Lab 02 - Question #1 solution

#include <iostream>
#include <fstream>
#include <cstring>

using namespace std;
const int NO_OF_QUESTIONS = 20;

//function to return grade given score
char examGrade(int score)
{
	float percent = ((float) score / (NO_OF_QUESTIONS * 2)) * 100;
	if (percent < 60)
		return 'F';
	else if (percent >= 60 && percent < 70)
		return 'D';
	else if (percent >= 70 && percent < 80)
		return 'C';
	else if (percent >= 80 && percent < 90)
		return 'B';
	else
		return 'A';
}

int main()
{
	char keyString[NO_OF_QUESTIONS + 1];
	char answerString[NO_OF_QUESTIONS + 1];
	char ID[9];
	char ch;

	int score;
	int len;
	ifstream infile;

	//should take this open to a function
	infile.open("Lab02_Q01_Data.txt");
	if (!infile)
	{
		cout << "Cannot open the input file. Program terminates!"
			<< endl;
		return 1;
	}

	cout << "Processing Data" << endl << endl;
	infile.get(keyString, NO_OF_QUESTIONS + 1);

	cout << "Key: " << keyString << endl << endl;
	cout << endl << endl;
	cout << "  ID " << "\t\tAnswers \tScore \t\tGrade" << endl << endl;
	//reading the first line
	while (!infile.eof())
	{
		score = 0;

		infile >> ID;
		infile.get(ch);
		infile.get(answerString, NO_OF_QUESTIONS + 1);

		for (int i = 0; i < NO_OF_QUESTIONS; i++)
		{
			if (answerString[i] == keyString[i])
				score += 2;
			else
				score--;
		}

		if (ID[0] != '\0')
			cout << ID << " " << answerString << "\t" << score << "\t\t" << examGrade(score) << endl;
	}

	return 0;
}