Short answer: Yes, CS questions are allowed, but only if they are mathematical in their focus.
Long answer: We are a math website. Thus, the questions you ask must be mathematical in nature. (Big surprise.) If your CS question is primarily mathematical, we will accept it here. If your CS question is asking about implementation, some feature of a specific language, etc., it will not be welcomed very nicely.
A good rule of thumb could be "Do I need to know how to program in language X in order to read or to answer this question?" If yes, then it's off topic. If no, then it's probably fine.
We don't like reading long listings of code; rather, please convert to pseudo-code before posting. We also shouldn't need to know anything about computer architecture to answer your question (e.g. "is this algorithm faster, because it's accessing the L2 cache, vs this one that's working in memory?" is not good).
Some history of this discussion: