//This is the Windows version of the student averages program. To compile on UNIX/Linux-based OSes, change any instance of "CLS" to "clear" and remove the system("PAUSE") line.
//This program will allow you to enter information on eleven students - names, and grades on five quizzes - and then it will calculate some averages.

//Call the input function - we're using a global structure for this, for ease of coding.
//After fetching input, we'll ask if they want to input another student. This is limited, as of present, to ten students - we have a counter not only as debug, but to allow the user to track how much has been input so they know what happens when the loop suddenly ceases.
//If the user says y/Y (thank you, tolower!) we will repeat the loop -- if the user says n/N, we will display the output.
//DispLaying output: this is tabulated for ease of reading.
//Calculate the overall averages in their own functions, and display them.

#include <iostream>
#include <string>
#include <cstring>
#include <iomanip>
#include <stdlib.h> // This is for cross-compatibility between OSes. system calls seemed to break on Linux without it.

using namespace std;

struct studentinfo
{
    string fname;
    string lname;
    int id;
    double tests[5];
    double average;
};


studentinfo students[10];
double overallavg[6];

void getinput (int counter);
char again (char resp);
void displayI (int counter, int stotal);
void displayII (int counter, int stotal);

int main() {

int counter; // god I worry about my coding ability sometimes
int stotal; // total students for display loop
char resp; // another Y/N loop

counter = 0; // Initialize it, as a precaution.

do {
    getinput(counter);
    resp = again(resp);
    counter++;
    stotal++;
} while (resp == 'y' && counter < 10);

system("CLS");
displayI(counter, stotal);
displayII(counter, stotal);
system("PAUSE");
}

void getinput (int counter) {
//This function merely reads the user's input - First & last names, ID number (for sake of expansion later on), and the five test scores.
       int i;
       int testno;
       testno = 0;
       cout << counter << " of 10 added\n\n";
       cout << "Enter the first name: ";
       cin >> students[counter].fname;
       cout << "Enter the last name: ";
       cin >> students[counter].lname;
       cout << "Enter the ID: ";
       cin >> students[counter].id;
       for (i=0;i<5;i++) {
       testno++;
       cout << "Enter the score for test " << testno << " of 5: ";
       cin >> students[counter].tests[i];
       }
       //And then we need to actually calculate the average... averages are stored in the student struct, again, for ease of coding (and organization).
       for (i=0;i<5;i++) students[counter].average+=students[counter].tests[i]/5;
}

void displayI (int stotal, int counter) {
//Display the bulk of the table. This includes headings, names, IDs, test scores, and per-student averages. Tabulated with \t for ease of reading, as well.
     int i;
     counter = 0;
     cout << setw(5) << left << "ID" << setw(40) << "Student Name" << setw(5) << right << "1" << setw(5) << "2" << setw(5) << "3" << setw(5) << "4" << setw(5) << "5" << setw(9) << "Average";
     cout << "\n"; // just to make things align better
// We're not using a for loop below - the screen is typically 80 characters on Windows / MS-DOS systems, and it would be tough to fit more tests.
     do {
     cout << setw(5) << left << students[counter].id << setw(40) << (students[counter].lname + ", " + students[counter].fname).substr(0,40) << setw(5) << right << students[counter].tests[0] << setw(5) << students[counter].tests[1] << setw(5) << students[counter].tests[2] << setw(5) << students[counter].tests[3] << setw(5) << students[counter].tests[4] << setw(9) << setprecision(3) << students[counter].average << "\n";
     counter++;
     } while (counter < stotal); // stotal: this increases with each student input, and its purpose is to tell this function when to stop. Also used in calculating overall averages.

}
void displayII (int stotal, int counter) {
// Calculate all of the overall averages, then display them. I would have done this in the main display function, and another way, but requirements called for it to have its own function.
    int i;
    counter = 0;
    do {
    for (i=0; i<5; i++) overallavg[i]+=students[counter].tests[i]/stotal;
    counter++;
    } while (counter < stotal);
    //overallavg[5] =
     for (i=0; i<5; i++) overallavg[5]+=overallavg[i]/5;
    cout << setw(45) << left << "Overall averages:" << setw(5) << right << overallavg[0] << setw(5) << overallavg[1] << setw(5) << overallavg[2] << setw(5) << overallavg[3] << setw(5) << overallavg[4] << setw(9) << overallavg[5] << "\n\n";
}

char again(char resp) {
// This function will ask if the user wishes to add another grade. (Ripped from the replace program, but what programmer doesn't reuse code when needed?)
//     char resp;
do {

cout << "\nAdd another? (Y/N, will repeat on other answers): ";
cin >> resp;
cin.ignore(50, '\n');
resp = tolower(resp); // Shift it to lowercase so there are fewer cases to test for.
} while (resp != 'y' && resp != 'n');
 system("PAUSE");
 system("CLS"); // Linux/UNIX users: replace CLS with clear
return resp;
     }