The occasional scrivener

Project Euler “is a series of challenging mathematical/computer programming problems that will require more than just mathematical insights to solve.” In other words, you need to get down and program to solve the problem[1].

I’ve recently reached Level 3 (solved over 100 problems) and thought I’d share some notes on what I’ve learned.

PE programming is “pure” programming, as in you’re working with algorithms and not systems. There’s rarely anything more complicated than file access needed. In fact, I’d say you need an aptitude for problem solving rather than programming, and the skills needed to solve PE problems are probably not really translatable to real work out in the real world, where you’re dealing with real people and real hardware and networks. To be sure, nowhere on PE do they say that this is programming in the wider sense, as opposed to Computer Science, but you’d be surprised how many CS grads think it does (I’m mocking you, Haskell nerds!).

The typical PE problem looks amenable to brute force, but it pays to research before jumping in. Wikipedia and Mathworld are great resources for a lot of the problems, often explaining the math behind them and sometimes having the algorithms you need.

Spoilers. I find it pretty hard to concentrate on a problem and not want to know the solution, especially when I’m into “grind” mode and just want to level up (this happens a lot with me and puzzle games too). There are plenty of spoilers around for the early problems (the ones that most people manage to solve) but as you move up they get sparser and sparser, and are usually in languages other than your chosen one. Often it’s enough for me to just get a hint. After you’ve solved a problem, you get access to a forum where others discuss their solutions. This can be an eye opener, but there’s no need to share your crappy solution if you don’t want to.

I use Perl. I thought of using PE to learn another language (Python), but finally I felt it was more fun to explore something I’m pretty proficient in than to learn something else. Perl has all the things you need for these problems (so far), especially as there are tons of libraries for specific applications. One of the more useful is Math::Pari, an interface to the Pari suite of numerical algorithms.

Perl is really nice for stuff like string manipulation and set operations. It’s also really easy to build ad-hoc data structures, although the syntax grows hairy really fast.

Python seems very popular among PE participants. Another popular language among the people who bother to post to answer threads is J), and of course Haskell has some vocal devotees.

I find it challenging and fun to work on these problems, and I encourage you to do the same!

[1] although there are some wizards who manage with pencil and paper, at least for the earlier problems.

This is SF author Bear’s foray into “the day after tomorrow” thrillers, featuring a future FBI hunting domestic bioterrorists. For some unexplained reason, the bureau is under political attack. This adds some artificial tension to the plot, but it’s mostly just something tacked on.

For other unexplained reasons, three inexperienced agents are thrown into the action directly from graduation. There’s some romantic tension between the young male protagonist and an attractive yet tortured older female agent, but this too feels tacked on.

Bear’s reason for writing this novel (as explained in an afterword) was to warn of the dangers of bioterrorism, specifically weaponised anthrax. He deserves credit for portraying Muslim characters with sympathy and understanding, and for crafting an exciting, competently written tale. But in the end it’s obvious he’s a bit out of his depth writing this kind of story.

This is the penultimate book in Erikson’s epic[1] “Malazan Book of the Fallen” cycle. This is the only fantasy cycle I’ve read and enjoyed since… well, the Lord of the Rings. However, Erikson subtly subverts the Manichean worldview of Tolkien and his epigones, introducing a gritty, smelly world of forces in precarious balance. It’s hard to describe, but it’s “realistic” in a way that Robert Jordan’s plastic world isn’t.

It helps that the writing is funny, and that Erikson has a good grip on both anthropology and military tactics.

“Dust of Dreams” is of necessity a cliffhanger, being but the first half of the end of the cycle. After reading this explosive tale I literally cannot wait for the sequel, “The Crippled God”. Highly recommended.

[1] for once, the word is used unironically.

Last month I didn’t post anything to this blog, which is the first time in its history I’ve missed a month. Looks like the little grid I coded can deal with null values: see here. It’s always good to have a test value for zero or null.

Well there’s a reason I haven’t been posting much, crazy work and not really anything else to talk about. I’ve started sharing stuff in Google Reader more though, and there’s always Twitter.

Here’s a random late winter/early spring pic to symbolize the season: