Help!

[Ana]

Hello, can somebody help me to make this method to run in O(n)
constant time. I think it is running in big O of n square, because of the space. Thank you.




// [[reverse the order of the elements of this list]]

public void reverse()
{
Node current = tail;
Node next = current.prev;
tail.prev = null;

do {
current.next = next;
Node temp = next;

next = temp.prev;
temp.prev = current;
current = temp;

}while (next != null);
current.next = null;

head = tail;
tail = current;
}

[doredson]

That is O(n). It only goes once through the list.