JMK 트레이더 레벨 1. 스킬포인트 뭐찍지?

Tough Water Level: CERC 2007

Numerical integration and formula parsing. At first, I started implementing Trapezoidal Rule; but it required an insane amount of formula evaluations; so I wrote code to generate parse tree to speed up evaluation. However, in the end, Simpson's Rule saved the day - it requires less than 50 intervals!

But, the amount of effort I threw into this code makes this worth posting anyway.

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Central Europe Regional 2007

PS2009 에서 돌음. Individual / first 4 hours. 6/793 으로 당시 랭크리스트 7등 성적. 하나만 더 풀었으면 4등인데 아깝당.. 잉 당시 1등인 Warsaw Eagles 는 9문제였는데 (시발) 당시 월드챔피언 -__ -

앞에서부터 풀겠다는 그릇된 욕망 때문에 괜히 C잡고 삽질하다가 고생했다. 코딩 매우 더러움.. ㅜㅜ 아직도 implementation 때문에 삽질을 많이 하는구나...

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ACM ICPC 2008 Aizu

Monday, the local practice session at Yonsei for the ACM competition used the problemset from Asia Regional Aizu 2008. I ended up solving six before leaving early; and I solved the rest of the set yesterday.

Summary: Tons of (possibly) interesting geometry problems.. but four geometry out of ten? And there are problems which require crazy long implementations; No wonder nobody solved more than eight. :-p I could have solved eight if I could complete competing, though.

Beware: long post ...

Prospect Theory

Prospect Theory: An ancient paper; a recommended read from the game theory course.

A Selection From MySQL Conferences Slides

• http://amix.dk/blog/viewEntry/19439

이중

• MySQL and Sphinx at Craiglist 란 게 있어서 봤는데, 전에 야후를 그만두고 CL 로 간 이 아저씨 의 발표자료. Sphinx 가 뭔가 해서 봤는데, C++ 로 만들고 SQL 을 백엔드로 하는 검색 엔진 -_-;

Simple Speed Test of AWS EC2 / Mosso

I've been tinkering with the idea of brute-forcing through this year's IPSC using some cloud computing services. Since many problems in IPSC require hours of computing time (of course, intended solutions can do it within minutes, but..), this might actually change the result of the game.

A few days ago I was extremely bored during an aesthetics class, so I paid 200 won to rent an hour of Amazon EC2 to see how good it performs. I also rented an hour from Mosso, a cloud service providing subsidiary of Rackspace. For comparison, I've run the same tests in my desktop, and my Linode VPS, and my school server, dev.

Of course, all my tests are not scientific (I didn't intend to and I didn't need to) so take this with a ton of salt.

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