## Monday, October 26, 2009

### A difficult problem ten years later

Here's another Russian IOI camp problem, this time one of the most difficult problems from the 1999 summer camp. Only one contestant was able to solve it back then. I wasn't. How does it look ten years later? I have testdata in case someone wants to actually write the solution :)

You are given eight pairs of numbers, x1, y1, x2, y2, ..., x8, y8. You need to find eight numbers z1, z2, ..., z8 such that (x1,y1,z1), (x2,y2,z2), ..., (x8,y8,z8) are the coordinates of the vertices of a cube with an integer side length, or to report that such numbers do not exist.

Apart from interesting problems and breathtaking competition, the algorithm contests have their own astonishing personalities. Let me introduce the today's hero: Gennady Korotkevich. His name is also spelled Henadzi Karatkevich sometimes.

He is 7th top ranked TopCoder Algorithm contestant. He's won IOI 2009 (got the highest score, not just gold medal which he did several times before that). He's beaten my team (which included another TopCoder ex-target!) at an ICPC-style contest this September. He's topped all Belarusian teams in the Western Quarterfinal for NEERC 2009.

And yet he's only 14. That means he has 2 or 3 more IOIs to go. That also means I have three more TopCoder Open tournaments to fight for before he arrives :)

What feels so good about Gena is that he doesn't seem to lose the rest of his life to programming contest training, at least according to the above interview. He reminds me of myself, but of course on a greater scale. While I'm sure he's training a lot, it's important that becoming a world-class master does not affect the other aspects of his life badly.

Gennady, if you're reading this, I challenge you for a game of soccer or table tennis :)

More generally, I think this example supports the idea that the skillset (or maybe talent? that's probably a question for a separate discussion) that the programming challenges require is unique and is only partially related to CS or mathematical higher education. And seeing how many big companies are valuing that skillset in job interviews, it seems important enough for education of future software engineers to maybe borrow something from the algorithm contests. Another possible direction, of course, is that algorithm contest puzzles were just lucky to get into the limelight, and will just go away (or maybe become a pure sport) at some point when the big companies and universities discover a better way to educate and recognize the future engineers. Somewhat like Formula 1 which is becoming less and less important for the development of normal cars.

## Sunday, October 25, 2009

### Torrent for screencasts

Okay, time to revive the blog.