Hi everyone! I would like very much to hear opinions about the best keyboard for coding. It would be nice to hear about specific keyboards that people have used already, about features that a good coding keyboard should have, and so on. I have been reading a while about such stuff, and everywhere the mechanical keyboards with those Cherry MX switches are heavily praised. I would like to hear a bit more from the programming community.

Thanks!

Please, help with this problem: suppose we are allowed to represent a set of binary strings (that is, consisting only of '0' and '1') with some other set of strings. In the latter set, we can use characters '0', '1' and 'X', where the character 'X' means that both '0' or '1' can occur in that position.

As a matter of example, we can represent the set {001,011,101} with the set {0X1,101}.

Now the problem: given a positive integer N and the set of all the possible binary strings of length N, what is the subset that is most difficult to represent? Here, difficult means that requires the largest amount of strings with the 'X' character allowed.

Thanks for the help.

P.S.: Since I realised that contribution is random and unfair, I don't give a f*** if I'm downvoted. This disclaimer is only for saving the time of downvoters.

Is there a simple way to access to all the submissions (or at least, accepted submissions) of some specific user? For example, I would like to save all my accepted submissions on my computer: how can I find (or download) them quickly?

Is there any chance that Matlab is included in the available languages for submitting in Codeforces? I understand that many of the features of Matlab would not result in something fair compared to the other available languages, but, anyway, I believe that even using the language as it is (excluding most of the "unfair" facilities) would be a VERY nice addition for many people. This is my humble opinion, and I would like to know the opinion of the community. Thanks to everyone.

EDIT: maybe the right addition would be Octave (which is mostly compatible), since Matlab is proprietary, as r__ pointed below. ****