title: A good bank of recursion solutions in C/C++/Java/C#
body: <p>I saw <a href="https://stackoverflow.com/questions/23860/what-is-the-best-way-to-learn-recursion">this question</a>, but the answers there are not very relevant.
  A friend needs a bank of solved recursion problems to help him study for a test <strong>tomorrow</strong>.</p>
  
  <p>He learned the issue theoretically, but is having problems grasping how to actually solve recursion problems. Do you know a good source of solved recursion problems (preferably in C, but can be in a C-style language as well) available on the net?</p>
  
  <p>Note - examples in functional languages will not help much here. My friend is in a study race to pass his test tomorrow, and I'm sure switching languages will just confuse him at this point (it might be educational on other, less stressed times).</p>