#include <iostream>

using namespace std;

////////////////////////////////////////////////////////////////////////////////

class VirtualArray
{
////////////////////////////////////////////////////////////////////////////////

protected:

    VirtualArray * next;
    int value;
    int position;

////////////////////////////////////////////////////////////////////////////////

public:

    VirtualArray()
    {
        next     = this;
        value    = 0;
        position = 0;
    }
    VirtualArray(int v1, int p1)
    {
        next     = this;
        value    = v1;
        position = p1;
    }

    ////////////////////////////////////////////////////////////////////////////

    VirtualArray * Add(VirtualArray * p1)
    {
        p1->next = next;
        next = p1;
        return p1;
    }

    void RemoveNext()
    {
        VirtualArray * rem = next;
        next = next->next;
        delete rem;
    }

    void Set(int pos, int val)
    {
        VirtualArray * curr = this;

        do
        {
            if (curr->position == pos)
            {
                curr->value = val;
                return;
            }
            curr = curr->next;
        }
        while (curr != this);

        Add(new VirtualArray(val, pos));

    }

    int & operator[](int pos)
    {
        VirtualArray * curr = this, * prev = NULL;

        do
        {

            if (curr->position == pos)
                return curr->value;

            prev = curr;
            curr = curr->next;

            if ((curr->value == 0) && (curr != this))
            {
                prev->RemoveNext();
                curr = prev->next;
            }
        }
        while (curr != this);

        return Add(new VirtualArray(0, pos))->value;

    }

    void Clear()
    {
        VirtualArray * curr = next, * prev = NULL;

        while (curr != this)
        {
            prev = curr;
            curr = curr->next;
            delete prev;
        }

        value = 0;
        next  = this;
    }

    int GetLenght()
    {
        VirtualArray * curr = next;
        int len = 1;

        while (curr != this)
        {
            len++;
            curr = curr->next;
        }

        return len;
    }

    void Shift(int p1, int m1 = 0)
    {
        VirtualArray * curr = this;
        int len = GetLenght();

        if (m1 && (m1 < len))
            m1 = len + 1;

        do
        {
            curr->position = (m1 ? (curr->position + p1) % m1 : (curr->position + p1));
            curr = curr->next;
        }
        while (curr != this);
    }

    void Print()
    {
        VirtualArray * curr = next;

        cout << "[" << value;
        while (curr != this)
        {
            cout << ", " << curr->value;
            curr = curr->next;
        }
        cout << "]" << endl;
    }

};

////////////////////////////////////////////////////////////////////////////////


int main()
{
    VirtualArray va1;
    for (int i=0; i<20; i++)
    {
        va1[i] = (i*9) % 10;
    }

    for (int i=0; i<20; i++)
        cout << "a[" << i << "] = " << va1[i] << endl;
    cout << "va1 = ";
    va1.Print();

    cout << "Shift on 1 element toward:" << endl;
    va1.Shift(1, 10);

    for (int i=0; i<20; i++)
        cout << "a[" << i << "] = " << va1[i] << endl;
    va1.Print();

    cout << "Count of elements = " << va1.GetLenght();
    getchar();
    return 0;
}