public void AddtoStart(int d)
{
DoublyNode new_node = new DoublyNode(d);
if (start == null)
{
start = new_node;
end = start;
}
else
{
start.prev = new_node;
new_node.next = start;
start = new_node;
}
size++;
}
public void AddtoEnd(int d)
{
DoublyNode new_node = new DoublyNode(d);
if (start == null)
{
start = new_node;
end = start;
}
else
{
new_node.prev = end;
end.next = new_node;
end = new_node;
}
size++;
}