#include "list.h"

List::List()
{
    _size = 0;

    header->data = 0;
    header->succ = trailer;
    header->pred = NULL;

    trailer->succ = NULL;
    trailer->pred = header;
}

Node List::predInsert(Node Old, int New)
{
    Node T = new node;
    T->data = New;
    T->succ = Old;
    T->pred = Old->pred;
    Old->pred = T;
    _size++;
    return T;
}
Node List::succInsert(Node Old, int New)
{
    Node T = new node;
    T->data = New;
    T->pred = Old;
    T->succ = Old->succ;
    Old->succ = T;
    _size++;
    return T;
}
void List::firstInsert(int New)
{
    Node T = new node;
    T->data = New;
    T->pred = header;
    T->succ = header->succ;
    header->succ = T;
    _size++;
}
void List::lastInsert(int New)
{
    Node T = new node;
    T->data = New;
    T->succ = trailer;
    T->pred = trailer->pred;
    trailer->pred = T;
    _size++;
}
Node List::predInsertN(Node Old, Node New)
{
    Node T = new node;
    T = New;
    T->succ = Old;
    T->pred = Old->pred;
    Old->pred = T;
    _size++;
    return T;
}
Node List::succInsertN(Node Old, Node New)
{
    Node T = new node;
    T = New;
    T->pred = Old;
    T->succ = Old->succ;
    Old->succ = T;
    _size++;
    return T;
}

Node List::firstInsertN(Node New)
{
    Node T = new node;
    T = New;
    T->pred = header;
    T->succ = header->succ;
    header->succ = T;
    _size++;
    return T;
}
Node List::lastInsertN(Node New)
{
    Node T = new node;
    T = New;
    T->succ = trailer;
    T->pred = trailer->pred;
    trailer->pred = T;
    _size++;
    return T;
}
Node List::find(int i)
{
    Node ans = first();
    for (int i = 0; i < _size; i++)
    {
        ans = ans->succ;
    }
    return ans;
}
int List::get(int i)
{
    return find(i)->data;
}