#include <iostream>   //needed for cout
#include "donlist.h"
using namespace std;

//**********************************************************
// Constructor.                                            *
// The argument passed to num indicates the number of      *
// elements in array passed to gifts. The gifts array      *
// holds the list of donation values. The constructor      *
// allocates the donations and arrPtr arrays. The gifts    *
// array is copied to the donations array. The elements    *
// of the arrPtr array are made to point to the elements   *
// of the donations array, and then sorted in ascending    *
// order by the selectSort function.                       *
//**********************************************************
DonationList::DonationList(int num, double gifts[])
{
    numDonations = num;
    if (num > 0)
    {
        // Allocate an array of doubles.
        donations = new double[num];
        // Allocate an array of pointers-to-doubles.
        arrPtr = new double*[num];
        // Initialize the arrays.
        for (int count = 0; count < numDonations; count++)
        {
            donations[count] = gifts[count];
            arrPtr[count] = &donations[count];
        }
        // Now, sort the array of pointers.
        selectSort();
    }
}

//**********************************************************
// Destructor frees the memory allocated by the constructor*
//**********************************************************
DonationList::~DonationList()
{
    if (numDonations > 0)
    {
        delete [ ] donations;
        donations = 0;
        delete [ ] arrPtr;
        arrPtr = 0;
    }
}

//************************************************************
// The selecSort function performs a selection sort on the   *
// arrPtr array of pointers. The array is sorted on the      *
// values its elements point to.                             *
//************************************************************
void DonationList::selectSort()
{
    int scan, minIndex;
    double *minElem;

    for (scan = 0; scan < (numDonations - 1); scan++)
    {
        minIndex = scan;
        minElem = arrPtr[scan];
        for(int index = scan + 1; index < numDonations; index++)
        {
            if (*(arrPtr[index]) < *minElem)
            {
                minElem = arrPtr[index];
                minIndex = index;
            }
        }
        arrPtr[minIndex] = arrPtr[scan];
        arrPtr[scan] = minElem;
    }
}

//*******************************************************
// The show function uses cout to display the donations *
// array in sequential order.                           *
//*******************************************************
void DonationList::show()
{
    for (int count = 0; count < numDonations; count++)
        cout << donations[count] << " ";
    cout << endl;
}

//*********************************************************
// The showSorted function uses cout to display the values*
// pointed to by the elements of the arrPtr array. Since  *
// arrPtr is sorted, this function displays the elements  *
// of the donations array in ascending order.             *
//*********************************************************
void DonationList::showSorted()
{
    for (int count = 0; count < numDonations; count++)
        cout << *(arrPtr[count]) << " ";
    cout << endl;
}