Recently, we received two project Euler questions:

I won't claim they are off-topic here. In fact, they often make exemplary Mathematica questions. However, I feel it goes against the spirit of project Euler to answer those questions here. The project is a large set of programming puzzles paired with a forum per question, open to anyone who has already solved a given puzzle. The project Euler spirit is all about DIY and learn from that, or solve it badly, go to the forum and learn from there.

We shouldn't be providing an open forum where anyone can scoop up the recipes.

  • @J.M. If I distilled it correctly the communis opinio over there is that Euler questions should be closed. Commented Aug 29, 2012 at 11:16
  • Yeah, pretty much; given the wording in the posting Will Jagy linked to in there, it seems that closure might be one avenue we can pursue here, but maybe the other guys here have better ideas... Commented Aug 29, 2012 at 11:20
  • @j.m. Given that they are fully acceptable as per FAQ, I'm not going to close unless we have a strong opinion on this among our users. There might be a copyright issue, though. I can imagine that it is not allowed to post a project Euler question here unless it is paraphrased. Text is protected but the ideas cannot be copyrighted (only patented). Commented Aug 29, 2012 at 11:26
  • Closing is not enough if we don't want spoilers. Someone could post an answer while the Q is still open, or worst, anytime in the comments. It should be deleting ... but those little problems are so cute! Commented Aug 29, 2012 at 11:40
  • The SE Q&A format doesn't appear to encourage the hint-giving approach that would be appropriate for these questions. Even when the questioner says "don't give me the solution, just give me a hint", they'll still get one or more complete answers. 'Tis human nature. But are "hint" answers considered sufficient?
    – cormullion
    Commented Aug 29, 2012 at 11:58
  • 8
    Being that part of the spirit is "solve it badly, go to the forum and learn from there." I think questions like the second that don't ask for a solution but for methods to improve a solution are quite in line with this. I doubt that the Euler forums are as great a Mathematica resource as this site. That being said, cheating at the questions is not hard, many answers can be found on google. I would not consider working code apearing here to be a big problem. I would still suggest changing the titles and text to not reflect the origin, and just state the questions however.
    – jVincent
    Commented Aug 29, 2012 at 11:59
  • I agree that it is very easy to stumble upon sites dedicated to the answering of project Euler questions (even without searching). Project Euler spirit is clear, but do they have a stated opinion, on their web page, concerning the exposure of solutions outside their forum? Also, if I'm not mistaken, their forum closes once the theme is well discussed/developed. This means that future versions of Mathematica, or new approaches cannot be treated on their official site.
    – P. Fonseca
    Commented Aug 29, 2012 at 12:29
  • I wouldn't mind seeing a standardized flashing banner (animated gif, or something else that clear catches the readers' attention) that would be placed at the beginning of the post, warning that, within the spirit of project Euler, the content should not be seen by those who are currently solving or pretend to solve, in the future, that particular question/level (and for politeness, we could add our moderators excuse: "the question was accepted because..."). Should I add this as an answer? Also, I think that leaving the questions can be a good publicity for the project (and MMA user stats).
    – P. Fonseca
    Commented Aug 29, 2012 at 12:41
  • @P.Fonseca I don't think anyone engaged with PE would think that reading answers anywhere on the net was in the spirit of the site. A flashing banner will be redundant for them and annoying for everyone else.
    – jVincent
    Commented Aug 29, 2012 at 12:58
  • 1
    I agree with @jVincent: removing the reference to Project Euler and the task number should be enough. I don't think we ought to turn away good questions just because somebody might be annoyed that the problems are being discussed outside of the official forum (and mostly they're so generic that I can't really see any copyright issues either). ... Commented Aug 29, 2012 at 14:33
  • 1
    @cormullion actually that works quite well for homework questions. So, in the spirit of teaching people to fish, I suggest partial solutions only. Obviously, it has to something adhered to, and not easily enforced, but I think it falls into that category quite well.
    – rcollyer
    Commented Aug 29, 2012 at 19:42
  • 2
    I think it's a good idea to edit the question to remove any explicit references to Project Euler, and to rephrase any verbatim copy of the problem text. Beyond that though, I think these questions should be treated like any other question on the site. Closing or deleting effectively makes PE an ever growing blacklist of forbidden questions. Suppose someone wants to find all the right angled triangles with a given perimeter. Do we close the question because they might be attempting PE #39? Commented Aug 30, 2012 at 12:06
  • 2
    @J.M. Perhaps we should also consider a project-euler tag (like they have on math.se? That way people can easily follow/block such questions...
    – Ajasja
    Commented Aug 30, 2012 at 12:19
  • 2
    @Ajasja I went ahead and tagged the questions with project-euler and will create a wiki page for it. Commented Sep 2, 2012 at 0:05

3 Answers 3


Please upvote this answer if you think it's ok to give code-complete answers to Project Euler questions.

  • 2
    I don't really understand why people are so secretive about their Project Euler solutions. It's a site to entertain and educate yourself, it's nice to try out new languages with it, it's nice to have some example problems you can heavily optimize. It hurts nobody to share the answers, complete with a load of comments in 100 languages, but it can be greatly beneficial; and most importantly, the only one you can cheat on is yourself if you're looking code up prematurely.
    – David
    Commented Sep 16, 2012 at 21:59
  • You loose the challenge of figuring it out yourself, which is ultimately why you do it.. Commented Nov 19, 2013 at 13:44
  • Haha clever answer
    – rassa45
    Commented Aug 14, 2015 at 14:06

To summarize the discussion, please upvote this answer if you agree that Project Euler questions are on-topic on the site, but that we should strive not to give a complete answer, but rather, give partial solutions that teach the questioner about Mathematica, like this one.

  • 4
    I didn't upvote this, but I'm not downvoting it either. I think we can take it as read that nobody wants to spoil other people's fun, so I think the type of answer given should depend on the way in which the question was asked. If the poster says they have no idea how to proceed, giving hints is best IMO. On the other hand, if they post a working solution that they want to optimize or improve, or see other solutions using different approaches, full answers seem entirely appropriate. Commented Aug 30, 2012 at 13:57

Please upvote this answer if you think Project Euler questions should be closed as off-topic (or "too localized").

  • It really is too late in time because answers litter the internet (with and without how the answers were actually obtained), but the authors of the Project Euler state on the site that they wish people did not do it. It comes down to does the author's wishes have any merit within the rules of this site. On SO, we have considered this many times, especially when other site wishes to use SO exclusively as their help forum. In SO case, just because someone else said its ok does not mean the exchange site has any obligation. In our case though, listen to the authors.
    – demongolem
    Commented Dec 23, 2015 at 1:16

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .