/* program to read data into a two-dimensional array */
#include <iostream>
#include <fstream>
#include <cstdlib>          //needed to use exit() function
using namespace std;

const int MAXSIZE = 50;
const int NUMEXAMS = 4;

//function prototypes
void findstudentavg(int grade[][NUMEXAMS], int class_size);
void findexamavg(int grade[][NUMEXAMS], int class_size);

int main()
{
    int grade[MAXSIZE][NUMEXAMS];
    int class_size;

    //un-comment to redirect cin to a file
    //ifstream cin("c:\\bc\\CISC1110\\pgms\\chapter7\\myinput2.txt");

    cout << "How many students in the class? ";
    cin >> class_size;
    cout << endl << "There are " << class_size << " students in the class" << endl;

    // read in and print the exam grades for each student
    cout << endl;
    for (int stnum = 0; stnum < class_size; stnum++)
    {
        cout << "Type in four grades for student " << stnum << endl;
        for (int exam = 0; exam < NUMEXAMS; exam++)
        cin >> grade[stnum][exam];
        cout << "The grades for student " << stnum << " were:";
        for (int exam = 0; exam < NUMEXAMS; exam++)
        cout << " " << grade[stnum][exam];
        cout << endl;
    }

    //find the student averages
    cout << endl;
    findstudentavg(grade,class_size);

    //find the exam averages
    cout << endl;
    findexamavg(grade,class_size);

//  system("pause");    //un-comment when using DevC++
    return 0;
}

/* Function findstudentavg()
 * Input:
 *  grade - a 2-dimensional array of grades
 *  NUMEXAMS - numbers of exams for each student
 *  class_size - number of students in the class
 * Process:
 *  finds each student's average
 * Output:
 *  prints each student's average
 */
void findstudentavg(int grade[][NUMEXAMS], int class_size)
{
    int sum;
    double avg;

    for (int stnum = 0; stnum < class_size; stnum++)
    {
        sum = 0;
        for (int exam = 0; exam < NUMEXAMS; exam++)
            sum += grade[stnum][exam];
        avg = (double)sum/NUMEXAMS;
        cout<< "Student " << stnum << " had an average of " << avg << endl;
    }
    return;
}

/* Function findexamavg()
 * Input:
 *  grade - a 2-dimensional array of grades
 *  NUMEXAMS - numbers of exams for each student
 *  class_size - number of students in the class
 * Process:
 *  finds the class average on each exam
 * Output:
 *  prints the class average on each exam
 */
void findexamavg(int grade[][NUMEXAMS], int class_size)
{
    int sum;
    double avg;

    for (int exam = 0; exam < NUMEXAMS; exam++)
    {
        sum = 0;
        for (int stnum = 0; stnum < class_size; stnum++)
            sum += grade[stnum][exam];
        avg = (double)sum/class_size;
        cout << "Exam " << exam << " had a class average of " << avg << endl;
    }
    return;
}