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trouble changing 1-D array into 2-D

fg8ty64 (7)
I have a program for finding the grades in a class of 10 students that uses 1-D arrays. My code is posted below. How do I convert it into 2-D array? Below the code, I gave an example of how I tried to do it, but I don't think I'm going about it right. Please help.

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

using namespace std;

float calculateExams (float[]);
float calculateFinal (float);
float calculateProjects (float[]);
float calculateQuizzes (float[]);
void letterGrade (float[], int&, int&, int&, int&, int&, char&);

int main ()
{
	ifstream inFile;
	ofstream outFile;
	inFile.open ("myInput.txt");
	outFile.open ("result.txt");

    int A = 0, B = 0, C = 0, D = 0, F = 0, x = 0, t;
    char letter;
    string first, last;
	float exams[3], final, projects[8], quizzes[5], average[5];
    
    while (x < 10)
    {
        t = 0;
		inFile >> first >> last;

		for(int m = 0; m < 3; m++)
		{
			inFile >> exams[m];
			if (exams[m] < 0)
			{
				t++;
			}
		}

		inFile >> final;
		if (final < 0)
		{
			t++;
		}

		for(int m = 0; m < 8; m++)
		{
			inFile >> projects[m];
			if (projects[m] < 0)
			{
				t++;
			}
		}

		for (int m = 0; m < 5; m++)
		{
			inFile >> quizzes[m];
			if (quizzes[m] < 0)
			{
				t++;
			}
		}

		if (t > 0)						
		{
			outFile << "Incorrect data for " << first << ' ' << last << endl << endl;
			x++;
			continue;
		}

		average[0] = calculateExams(exams);
		average[1] = calculateFinal (final);
		average[2] = calculateProjects (projects);
                average[3] = calculateQuizzes (quizzes);
		letterGrade (average, A, B, C, D, F, letter);

		outFile << fixed << showpoint << setprecision(2)
			<< first << ' ' << last << " has a(n) " << letter << " with a "
			<< average[4] << "% for this course.  His/Her grades are: " << endl
			<< "Percentage of exams: " << average[0] << "%" << endl
			<< "Percentage of final: " << average[1] << "%" << endl
			<< "Percentage of projects: " << average[2] << "%" << endl
			<< "Percentage of quizzes: " << average[3] << "%" << endl << endl;
		x++;
	}

	outFile << "Total A's: " << A << endl
		<< "Total B's: " << B << endl
		<< "Total C's: " << C << endl
		<< "Total D's: " << D << endl
		<< "Total F's: " << F << endl;

    return 0;
}

float calculateExams (float ex[])
{
	float sum = 0;
	for (int k = 0; k < 3; k++)
		sum += ex[k];
	return (sum/300) * 30;

}
	
float calculateFinal (float fin)
{
	return (fin/100)* 30;
}

float calculateProjects (float proj[])
{
    float sum = 0;
    for (int k = 0; k < 8; k++)
         sum += proj[k];
    return (sum/400) * 30;
}

float calculateQuizzes (float q[])
{
	float sum = 0;
	for (int k = 0; k < 5; k++)
		sum += q[k];
	return (sum/100) * 10;
}
    
void letterGrade (float scr[], int& A, int& B, int& C, int& D, int& F, char& l)
{										
	scr[4] = scr[0] + scr[1] + scr[2] + scr[3];

int factor = int(scr[4]/10);

    switch (factor)
    {
         case 10: case 9: {l = 'A';
                          A++;
                          }
                          break;
         case 8: {l = 'B';
                          B++;
                          }
                          break;
         case 7: {l = 'C';
                          C++;
                          }
                          break;
         case 6: {l = 'D';
                          D++;
                          }
                          break;
         default: {l = 'F';
                          F++;
                          }
    }
}


For each function, I changed the for loop to a nested for loop. For example, for the function calculateQuizzes, I changed it to:
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float calculateQuizzes (float q[][])
{
   float sum = 0;
   for (int r = 0; r < 10; r++)
      for (int c = 0, c < 5; c++)
      sum += q[r][c];
   return (sum/100) * 10;
}

...and then up in the function declarations above the main, I changed it to "float calculateQuizzes (float[][]);". But there's got to be more to it than that! What else do I need to do?
firedraco (6243)
I don't think you are doing this correctly...I think what you want to do is have an array that contains the Quizes/Finals/Projects/Exams arrays. If you don't add any more arrays, you could just make something (like an enum or const ints) to map the 0, 1, 2, and 3 values, and put the Quizzes etc in their respective areas. Then for your other functions you will have to reference the const ints/enums to access the correct row of the array to get the data out.
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