Final_Node (LinkedList)

#include <iostream>
using namespace std;

struct List
{
    int data;
    List* next;
    List* previous;
};

class Node
{
private:
    List* first;
    List* last;
public:
    Node()
    {
        first = NULL;
        last = first;
    }
    ~Node();
    void push(int n);
    void root();
    void shift();
    void unshift(int n);
    void pop();
};

void Node::push(int n)
{
    List *temp = new List;
    temp->next = NULL;
    temp->data = n;

    if (first != NULL)
    {
        temp->previous = last;
        last->next = temp;
        last = temp;
    }
    else
    {
        temp->previous = NULL;
        first = last = temp;
    }

}

void Node::root()
{
    List* current = first;
    while (current)
    {
        cout << current->data << "->";
        current = current->next;
    }
    cout << "NULL" << endl << endl;
}

void Node::unshift(int n)
{
    List* temp = new List;
    temp->data = n;
    temp->next = first;
    temp->previous = NULL;
    first->previous = temp;
    first = temp;
}

void Node::shift()
{
    List* temp = first;
    first = first->next;
    delete[] temp;
}

void Node::pop()
{
    List* temp = last;
    last = last->previous;
    last->next = NULL;
    delete[] temp;
}

Node::~Node()
{
    while (first)
    {
        last = first->next;
        delete[] first;
        first = last;
    }
}

int main()
{
    Node list;
    int n;
    cout << "-----Push-----" << endl;
    for (int i=1;i<6;i++)
    {
        list.push(i);
        list.root();
    }
    cout << "-----Shift-----" << endl;
    for (int i=1;i<5;i++)
    {
        list.shift();
        list.root();
    }
    cout << "-----Unshift-----" << endl;
    for (int i=1;i<6;i++)
    {
        list.unshift(i);
        list.root();
    }
    cout << "-----Pop-----" << endl;
    for (int i=1;i<6;i++)
    {
        list.pop();
        list.root();
    }
    return 0;
}