Question: Do you know any online problem sets or contests that accept solutions in Haskell? I know only [El Judge](http://acm.mipt.ru/twiki/bin/view/ELJudge/WebHome), but unfortunately it has some problems with ghc, so any Haskell problem is rejected with "memory limit" resolution.

Answer: 
Check out [99 haskell problems](http://www.haskell.org/haskellwiki/H-99%3a_Ninety-Nine_Haskell_Problems)
[Coderforces.com](http://codeforces.com/)

You can also see how others have solved a problem using Haskell, e.g., submissions by [watashi](http://codeforces.com/submissions/watashi) and [jbin](http://codeforces.com/submissions/bjin) (jbin and watashi are both ACM-ICPC world finals champions, in 2012 and 2010 respectively.)

jbin's github: <https://github.com/bjin/puzzles>