#include <iostream>
#include <fstream>
using namespace std;
 
int** createArray(int rows, int cols);
void readData(int** dataArray, ifstream& file_in, int rows, int cols);

// Prototypes for functions you will write
void printOneGrade     (int **grades, int rows, int cols, int student, int assignment);
void printOneStudent   (int **grades, int rows, int cols, int student);
void printOneAssignment(int **grades, int rows, int cols, int assignment);
 
int main() {
        // Constants -- to keep simple we assume 10 students and 12 assignments
        const int ROWS = 10; // number of students
        const int COLS = 12; // number of assignments

        // Create 2D array and read grades in
        // grades[i][j] will be grades of i'th student on j'th assignment
        int **grades = createArray(ROWS, COLS);
        ifstream fin("grades.txt");
		if (!fin)
		{
			cout << "ERROR: could not open file grades.txt\n";
			exit(1);
		}

        readData(grades, fin, ROWS, COLS);
 
        char ch;
        do {
            // Ask user what they want to know about
            int student, assignment;
            cout << "Enter student number [0.. " << ROWS-1 << "]: ";
            cin >> student;
            cout << "Enter assignment number [0.. " << COLS-1 << "]: ";
            cin >> assignment;
            
            // Print out different info about the student and assignment
            printOneGrade     (grades, ROWS, COLS, student, assignment);
            printOneStudent   (grades, ROWS, COLS, student);
            printOneAssignment(grades, ROWS, COLS, assignment);
        
            // Should we continue?
            cout << "Continue? (y/n) ";
            cin  >> ch;
        } while (ch == 'y');
        return 0;
}
 
int** createArray(int rows, int cols) {
        int** dataArray = new int*[rows];
        for (int i = 0; i < rows; i++)
        {
               dataArray[i] = new int[cols];
        }
        return dataArray;
}
 
// Read data -- assumes each row of input is one student.  Each column is an assignment
void readData(int** dataArray, ifstream& file_in, int rows, int cols) {
        for (int i = 0; i < rows; i++) {
                       for (int j = 0; j < cols; j++)
               {
                       file_in >> dataArray[i][j];
               }
        }
}    

// Prints grade for the given student and assignment
// e.g. "Grade for student 1 on assignment 3 is 74";
void printOneGrade     (int **grades, 
						int rows, 
						int cols,
						int student,
						int assignment)
{
	cout << "Grade for student " << student 
		<< " on assignment " << assignment
		<< " is " << grades[student][assignment];
}


// Prints all grades for the given student
// e.g. "Grades for student 1 are:
//       96	67	56	74	94	100	98	68	95	65	82	80"
void printOneStudent   (int **grades, int rows, int cols, int student)
{
	int i;
	cout << "Grades for student " 
		<< student << " are: " << endl;
	for(i=0;i<cols;i++)
	{
		cout << grades[student][i] << " ";
	}
}


// Prints all grades for the given assignment
// e.g. "Grades for assignment 3 are:
//       72 74 59 69 67 54 71 89 95 100"
void printOneAssignment(int **grades,
						int rows, int cols, 
						int assignment)
{
	int i;
	cout << "Grades for assignment " 
		<< assignment << " are: " << endl;
	for(i=0;i<rows;i++)
	{
		cout << grades[i][assignment] << " ";
	}
}