Eine kleine ECOOpractice

[Cyril]

Here is (one of) our school's ECOO team selection contests, which we held today. Problem D is by Kevin Yu from Don Mills CI. AJ tested problem B for me back in the day. I wrote problems A, B, and C.

It's not extremely hard, but it is an attempt to incorporate what you would expect from these competitions:

- geometry
- number theory
- super brute force
- ad-hoc stuff
- a bit of classical stuff
- easy problem with algorithm given
- graph problems
- irrelevant stories

contest paper: [http://cyrilzhang.com/wp-content/uploads/2011/03/DMCI_Contest_Mar2011.pdf]
test data + solutions: [http://cyrilzhang.com/wp-content/uploads/2011/03/DMCI_Contest_Mar2011.zip]

Have fun. :)