He has the classic "find a loop in a linked list" question here:<p><a href="http://www.mytechinterviews.com/loop-in-a-singly-linked-list" rel="nofollow">http://www.mytechinterviews.com/loop-in-a-singly-linked-list</a><p>He seems to think it's the end of the story when he trots out the usual "tortoise and hare" algorithm, without mentioning that it's more efficient to use a teleporting tortoise.