// This program illustrates the use of constructors
// and destructors in the allocation and deallocation of memory.
#include <iostream>
#include <string>
using namespace std;

class Squares
{
private:
    int length;  // How long is the sequence
    int *sq;     // Dynamically allocated array
public:
    // Constructor allocates storage for sequence
    // of squares and creates the sequence
    Squares(int len)
    {
        length = len;
        sq = new int[length];
        for (int k = 0; k < length; k++)
        {
            sq[k] = (k+1)*(k+1);
        }
        // Trace
        cout << "Construct an object of size " << length << endl;
    }
    // Print the sequence
    void print()
    {
        for (int k = 0; k < length; k++)
            cout << sq[k] << "  ";
        cout << endl;
    }
    // Desctructor deallocates storage
    ~Squares()
    {
        delete [ ] sq;
        // Trace
        cout << "Destructor for object of size " << length <<  endl;
    }
};

//***********************************************
// Outputs the sequence of squares in a         *
// Squares object                               *
//***********************************************
void outputSquares(Squares *sqPtr)
{
    cout << "The list of squares is: ";
    sqPtr->print();

}
int main()
{
    Squares sqs(5);
    cout << "The first 5 squares are: ";
    sqs.print();

    // Main allocates a Squares object
    Squares *sqPtr = new Squares(3);
    outputSquares(sqPtr);
    // Main deallocates the Squares object
    delete sqPtr;

    return 0;
}