// Sean Anderson
// CS 151, 1/22/2017
// CH10, PC2
/*
Modify the program of Programming Challenge 1 to allow the user to enter name-score
pairs. For each student taking a test, the user types a string representing the name of the
student, followed by an integer representing the student's score. Modify both the sorting
and average-calculating functions so they take arrays of structures, with each structure
containing the name and score of a single student. In traversing the arrays, use pointers
rather than array indices.
*/

#include <iostream>
#include <string>
using namespace std;

struct Student
{
    string name;
    double grade;
};

// Function Prototypes
double average(Student *, int);
void sort(Student*, int);

int main()
{
    int numberOfScores;
    Student *testScores;     // Pointer to dynamically allocated array of scores
    double ave;              // Average scores

                             // Determine number of scores and allocate array
    cout << "Number of scores that you will input: ";
    cin >> numberOfScores;
    testScores = new Student[numberOfScores];

    // Get scores from the user
    for (int count = 0; count < numberOfScores; count++)
    {
        cout << "Student #" << (count + 1) << endl;
        cout << "    Name: ";
        //cin >> testScores[count].name;
        cin >> (testScores + count)->name;

        do {
            cout << "    Score: ";
            cin >> (testScores + count)->grade;

            if ((testScores + count)->grade < 0)
            {
                cout << "Please only enter scores greater than 0.";
            }
        } while ((testScores + count)->grade < 0);
    }

    // Echo scores back to user
    cout << "\nThe test scores that you entered: ";
    for (int count = 0; count < numberOfScores; count++)
    {
        cout << "\n Test #" << (count + 1) << ": " << (testScores + count)->name << ": " << (testScores + count)->grade;
    }

    // Sort students based on their grade using a bubble sort function
    sort(testScores, numberOfScores);

    // Print the sorted scores
    cout << "\n\nThe test scores after being sorted: ";
    for (int count = 0; count < numberOfScores; count++)
    {
        cout << " " << (testScores + count)->grade;
    }

    // Computer average
    ave = average(testScores, numberOfScores);

    // Print the output
    cout << "\nThe average test score was: " << ave << endl;

    cout << "Press any key to exit.." << endl;
    cin >> ave;

    // Delete the array
    delete[] testScores;
    testScores = 0;
    return 0;
}

double average(Student *testscores, int numberOfScores)
{
    double total = 0;

    for (int count = 0; count < numberOfScores; count++)
    {
        total += (testscores + count)->grade;
    }

    return total / numberOfScores;
}

//This is a simple bubble sort that sorts the students by their grades.
void sort(Student *students, int nbrScores)
{
    Student temp;
    for (int i = 0; i < nbrScores; i++)
    {
        for (int j = 0; j < nbrScores; j++)
        {
            if ((students + i)->grade > (students + j)->grade)
            {
                temp = *(students + i);
                *(students + i) = *(students + j);
                *(students + j) = temp;
            }
        }
    }
}

struct Point {
    double x, y;

    struct Point& operator+=(const Point& rhs)
    {
        x += rhs.x; y += rhs.y;
        return *this;
    }

    struct Point& operator+=(const double& k)
    {
        x += k; y += k;
        return *this;
    }
};

Point operator+(Point lhs, const Point& rhs)
{
    return lhs += rhs;
}
Point operator+(Point lhs, const double k)
{
    return lhs += k;
}
Point operator+(const double k, Point rhs)
{
    return rhs += k;
}