Brain training for programmer

Question

Do you know a brain training website for programmers.
I want to improve my programming skills.

Answer 1

Solve problems on hacker rank,hacker earth, codevita, codechef, codeforces try to contribute on geeks for geeks by publishing your own code and try to apply the concepts of (data structures and algorithms) like stack,queues,arrays in real life application systems.

I think this much is enough to build a good problem solving skill :)

Answer 2

Codeforces - best website