I think this is just one of the pitfalls that the author points out: it is not the sheer number of possibilities that defines the difficulty of a problem. He links to his previous blog post<p><a href="http:&#x2F;&#x2F;mat.tepper.cmu.edu&#x2F;blog&#x2F;?p=6995" rel="nofollow">http:&#x2F;&#x2F;mat.tepper.cmu.edu&#x2F;blog&#x2F;?p=6995</a><p>with a nice example: sorting.<p><i>“Sorting a bunch of numbers!  Hoo-wee, that’s a hard one.  If I had 1000 numbers, I would have to check all orderings of the numbers to find the sorted order.  That is 1000</i>999<i>998</i>…<i>2</i>1 orders and that is more than the hairs on a Hobbit’s toes.”<i>