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#include <fstream>
#include <string>
#include <sstream>
#include <iostream>
#include <iomanip>

using namespace std;

int main(int argc, char **argv)
{
	// input files (answerKey.dat), (studentTest.dat)
	ifstream infile;
	ifstream student;
	// output file (finalScore.dat)
	ofstream outfile;

	// iterator for correct answers
	int correctCount = 0;

	// error checking for input and output files
	//make sure we can open the files
	infile.open("answerKey.dat", ios::in);
	if (!infile)
	{
		cout << "Unable to open the file " << infile << endl;
		return -1; //error
	}
	student.open("studentTest.dat", ios::in);
	if (!infile)
	{
		cout << "Unable to open the file " << student << endl;
		return -1; //error
	}
	outfile.open("finalScore.dat", ios::out);
	if (!outfile)
	{
		cout << "Unable to open the file " << outfile << endl;
		return -1; //error
	}

	// count the number of lines in the infile (use in break for outfile)
	// Forward declaired variables for counting lines in file
	char value[1024] = {0};
	unsigned int count = 0;
	FILE *file = fopen("studentTest.dat", "r");
	if(file == NULL)
	{
		//error
		return -1;
	}
	size_t read_count; // This stores the count of bytes read
	// Read 1024 bytes at a time
	while((read_count = fread(value, 1, 1024, file)) > 0) 
	{
		for(unsigned int i = 0; i < read_count; ++i)
		{
			// Increment count for each end of line character
			if(value[i] == '\n') 
				++count;
		}
	}
	// output number of lines
	cout << "The input file has " << (count + 1) <<" lines." << endl;
	// close the file for line counting
	fclose(file);

	// set linenum for line processing
	int linenum = 0;

	// build the body of the outfile
	while(!infile.eof())
	{

		// open the student's written answers
		while(!student.eof())
		{
			// declare student's answer line
			std::string studentLine;

			// get answer line
			std::getline(student, studentLine);
			std::string studentAns = studentLine;

			// declare answerKey line
			std::string ansLine;

			// get answerKey line
			std::getline(infile, ansLine);
			std::string answer = ansLine;

			if (ansLine.size() <= 1) { // break out because it's blank
				break;
			} else { // made it! now process the lines

				if (studentLine.size() <= 1) { // break out because it's blank
					break;
				} else { // made it! now process the lines

					// increment linenum for file processing
					linenum++;

					// compare the strings for appropriate answers
					if ((strcmp( answer.c_str(), studentAns.c_str())==0))
					{
						// got the correct answer
						correctCount++;
						cout << linenum << " CORRECT" << endl;
						outfile << linenum << " CORRECT" << endl;
					}
					else
					{
						// got the wrong answer
						cout << linenum << " WRONG" << endl;
						outfile << linenum << " WRONG" << endl;
					}

					// break out when we reach the end of file to avoid a stack error
					if (student.eof()) break;

				} // end of else

			} // end of inner while loop

			// break out when we reach the end of file to avoid a stack error
			if (infile.eof()) break;

		} // end of else
	} // end of outer while loop

	// output total number correct
	cout << "\nTotal number of correct answers: " << correctCount << endl;
	outfile << "\nTotal number of correct answers: " << correctCount << endl;

	cout << "End of file processing" << endl;

	// close the files that we used
	infile.close();
	student.close();
	outfile.close();
	return (0);
}

double finalScore = ( ( (double)correctCount / (double)linenum ) * 100 );