As a student, I'm looking for hard stuff to do for become a good programmer.
I've tried Personal Software Process (and I hate it), and now I'm improving myself with some agile kata on OOP in c++ and python.
But I like recursion. and I think a deep understanding of its fundamentals is required to be called a good programmer.
Can you recommend some exercises (or website, books, whatever) to practice recursion on a daily basis?