Findancestors problem.
Added spiral question and a more advanced one where you actually print out a non-square spiral.
Added Division, AToI, and OneEditDistance Away
Added Ramanujam numbers
Adding evaluation of infix arithmetic / boolean expressions question.

It's solved via two methods:
1. The boolean one represents converting the expression first into postfix, and then evaluating it.
2. The arithmetic one evaluates it directly using two stacks.
Implemented log tracking question where you need to keep track of the number or log hits in the past 5 minutes and
return the count if needed.
Renamed practical to inside puzzles
Added unit test for LoggingFiveMinutes as well as IllegalArgumentException if you try to log backwards
(ie. if you call getHits or logHit on a time that is before a time for which you previously called getHits or logHit)
Added Powerset and shortest complete string problem.
Merge branch 'master' of github.com:tonygwu/programming-puzzles