I tried to recover a password. When thinking of this I recognized that the problem "password recovery" is a very nice example of a NP problem. If you know the password it's very easy to verify it i...

I struggle to define the running time for the following algorithm in O notation. My first guess was O(n), but the gap between the iterations and the number I apply isn't steady. How have I incorrec...

I know that some of the capabilities of the Perl regular expression engine are not regular. However, what class is it? It might be context-free, but CS theory was never my strongest subject.