To the guys that are learning a language and ever ask about a problem to solve or an idea to a project.
- http://projecteuler.net/
- http://exercism.io/
- http://cryptopals.com/
- http://www.ic.unicamp.br/~meidanis/courses/mc336/problemas-lisp/L-99_Ninety-Nine_Lisp_Problems.html
- https://www.codingame.com/cg/
Enjoy it
Thanks, @mekhami. =]