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TopCoder, Math, and Game Programming

reiners writes "DevX.com has an interesting interview with David Arthur (dgarthur), the 2003 TopCoder Collegiate Challenge winner. Arthur discusses many interesting topics: the similarities between TopCoder problems and math problems, why TopCoder performance is positively correlated with 'real-life' programming performance, and why game programming is where the action is."

22 of 236 comments (clear)

  1. programming 3D rendering engine by stonebeat.org · · Score: 4, Interesting

    programming 3D rendering engine. that is where all the action is. i learned more about linear algebra while writting 3D rendering libraries, then i did during the course of my degree. :)

    1. Re:programming 3D rendering engine by RabidOverYou · · Score: 4, Funny

      I would rather have majored in Glass Chewing than Linear Algebra. Numerical Analysis was bad, but Linear Algebra ... ooh I get the shakes.

  2. beh by Anonymous Coward · · Score: 5, Funny
    game programming is where the action is
    Then why do I always have rendering operations rather than second dates in my pipeline?
  3. True "Top" Coders Dominate the "Bottom" Coders by Nova+Express · · Score: 4, Funny

    Top Coder: "What? This isn't done yet?"

    Bottom Coder: "No, your Code Mistressness!"

    Top Coder: "You pathetic little worm! Get back in there and code until your hands bleed!"

    Bottom Coder: "Right away your worshipfulness!"

    Expect to see more ads for "Dominatrix" pop up in Silicon Valley...

    --
    Lawrence Person (lawrencepersonh@gmailh.com (remove all "h"s to mail)

    http://www.lawrenceperson.com/

  4. Language of Choice by avdi · · Score: 4, Interesting

    I find it interesting that a math double-major, who's considering becoming a math professor, uses C++ as his language of choice, with Java coming second. Not Lisp, not Scheme, not Haskell - C++.

    I'm not sure what conclusion to draw from that fact, I just find it interesting.

    --

    --
    CPAN rules. - Guido van Rossum
    1. Re:Language of Choice by larry+bagina · · Score: 5, Funny
      TopCoder cofirms it: functional programming is dieing. You don't need to be Eliza to predict functional programming's future: functional programming is dieing. Scheme is the most endangered of them all, having suffocated under a deluge of ()s. It was auctioned off to gnu/emacs, anoter charnel house, with an equally precarious future. Induction proves that the downward spiral will continue until termination.

      Fact: functional programming is dead.

      --
      Do you even lift?

      These aren't the 'roids you're looking for.

    2. Re:Language of Choice by White+Shadow · · Score: 4, Insightful

      Did you read why C++ is his language of choice? The reason he gives is because it's the language he has the most experience in. In fact, most of top ranked competitors use C++ (you have a choice between C++, C# and Java). My theory on this isn't that most of them think that C++ is a better language, it's just that most of the top competitors went through school when C++ or C was being taught so they know it the best. Most (but not all) of the top ranked coders are at the ends of their undergraduate careers or older.

    3. Re:Language of Choice by jgerman · · Score: 3, Interesting
      Kids aren't taught functional languages in college much anymore. You can go through all four years, get a degree and know very little about even imperative programming. Object Orienting caught on at schools when it was at the height of it's buzzword curve and hasn't let go yet.


      I'm sure I'm not the only one working in the industry that's had to deal with poorly educated fresh out of college employees. Kids that only know one langauge, and one way of doing things.
      OTOH I don't believe I learned much from college, it was the reading and coding I did on the side.


      I wish when kids chose CompSci as a major, the first thing they got was a copy of Knuth, Godel Escher and Bach, the Planiverse, and the Turing Omnibus. (There are obviously others I'm leaving out for instance Programming Pearls, Hackers, ext.) I think it would go a long way towards a better Comp Sci education.

      --
      I'm the big fish in the big pond bitch.
    4. Re:Language of Choice by swillden · · Score: 4, Insightful

      In theory, C++ would be the worst of the three in a timed contest--too much housekeeping.

      Absolute nonsense.

      If you know C++ well, and use the language effectively, there is very, very little housekeeping. My C++ code probably has less housekeeping code than typical Java code, because destructors are an immensely useful tool. Toss in auto_ptr, a couple of other smart pointer types and a few design guidelines and C++ is very good at allowing you to focus on the problem, not the tool.

      Plus, I never have to remember to call "close()".

      Java has an edge not in the area of housekeeping (and, as you mentioned, Java is unpleasantly verbose, particularly with respect to all of the casting that is often required) but in the area of libraries. This gap isn't as large as some might think, though, because (a) many of the Java libs are rather poorly designed and make you work much harder than you should have to and (b) there are some decent libraries around for C++.

      --
      Note to ACs: I usually delete AC replies without reading them. If you want to talk to me, log in.
  5. Real World vs. Top Coder... by Xerithane · · Score: 4, Insightful
    Uh, you are asking a student who has held an Internship. His points are fairly valid:
    • Test your code
    • Make it readable
    • Spend time designing

    Those 3 don't happen as much in the real world as one would hope to think. Very few companies do code reviews correctly, nor do most programmers spend enough time testing their algorithms.

    I would look at a Top Coder victor the same way I would look at someone who can answer trivia questions correctly. The experience is incredibly valuable, but I wouldn't say that they are parallel at all. Most of the questions and tests are biased against people who have experience doing competitions. A veteran programmer would probably perform 10x better in a real world environment, and is much more valuable than a TopCoder winner who is still in school... but I could be wrong.
    --
    Dacels Jewelers can't be trusted.
  6. Re:good thing by SamBeckett · · Score: 5, Insightful

    hehe you must have scored REALLY bad on the competitions to have this kind of attitude. From my experience, I have a relatively average score (~1400) and have nothing but the utmost respect for the true "top coders". Being fast is just one part of it, algorithm knoweldge and language mastery is a must-have to be competitive like these guys are.

  7. how about encryption? by qortra · · Score: 5, Interesting

    It really depends on how you define "action". Encryption seems to me to be even more exciting a field. It isn't as glamorous as game programming, but the math involved is amazingly interesting (advanced number theory, primality), and good encryption tends to last for longer than good game engines.

    3D rendering is not entirely about math (probably a lot more to do with studying the brain and how people generally interpret images that they see). Encryption however is ALL math. Anyhow, that's my 2 cents.

    1. Re:how about encryption? by plierhead · · Score: 4, Funny
      Hah, encryption, I spit in your face !

      Payroll processing is where the action is. COBOL rocks! And you'll score loadsa chicks.

      --

      [x] auto-moderate all posts by this user as insightful

  8. Why am I not surprised ... by 1in10 · · Score: 5, Funny

    Wow, someone who won top coder is saying it's a good indication of real world ability.

    In other news, Microsoft says Windows is the most reliable, and George Bush says America is the best.

  9. Translation... by Duncan3 · · Score: 4, Funny

    In other words he's smart enough to know even he can't get a job programming, and so it's a waste of his time to try.

    A friend of mine hired two AMERICAN programmers for 6$/hr last week. I told him he could get them for $4/hr in India, but he doesn't like remote workers.

    The party is over. Move along.

    --
    - Adam L. Beberg - The Cosm Project - http://www.mithral.com/
  10. Re:good thing by Anonymous Coward · · Score: 3, Interesting

    Yup. There wasn't a challenge. I did them for awhile. When they used to pay for all competitions, I learned it was better to stay in the bottom ranks. There you could take a room on one question, the easiest because all you needed were language tricks. When it was just Java, this basically meant that you learned all of java.util and java.lang packages. Basically my strategy boiled down to this:

    1. Read the easy question.
    2. Recall the Java class/method that shortcutted the problem.
    3. Write 3-5 lines of code (not including the class and method header).
    4. Score near max points and be done before everyone else and sit for the rest of the round.
    5. Challenge round, slam the people that tried to finish as fast as you. Chances are these people made a mistake and if you knew the problem, you knew what to look for right away.

    Most of the time I'd also just open the last two questions so I knew what to expect if someone did finish them, but the bulk of the people in the lower rooms would never even get to finish them in the allotted time, if they did, you could almost always count on it being wrong. So long as I didn't answer the big questions and let my scores inflate, I never moved out of those rooms and I never saw a point in it. The only point I saw in getting to the higher rooms was to make the invitational. Yeah I'd love to win $100,000 but at 1 in 64 kids (back a year and a half), my odds weren't that good anyway even if I thought I was talented enough to win (which I know I'm not).

    This is not real world coding and I would NOT encourage colleges to become involved in Topcoder because most of their philosophies go directly against what professors are trying to instill in up and coming programmers. You are not encouraged to design, comment, test or even read the problem thoroughly in these competitions because it all costs you valuable points. Whether or not these are valuable skills in the real world, I'm still growing up and learning.

  11. nobody talks about the actual problems? by lingqi · · Score: 4, Interesting

    well after 69 comments (hehe), there has not been a SINGLE one discussing the competition problems, all three of which are quite interesting.

    especially the hard one, probably, because my mind is drawing a blank on how to have it implemented... (no i didn't cheat and look at the solution).

    heh, actually they go like this:

    *easy* - okay, i can think of a algorithm. probably not the fastest thing in the world, but it should work out.
    *medium* - have a haze of an idea on what an algorithm might look like. with enough caffine it MIGHT solidify.
    *hard* - at least I understand the problem, but curses on the restrictions of a binary tree =)... no idea on algorithm that would finish executing before the end of the universe. (granted, only 50 elements, so maybe it's possible brute-force)

    Damn; this is exactly how /. lowers productivity. making people spending way too much brain power on stuff that's completely unrelated and time consuming. heck; i might lose sleep over this.

    --

    My life in the land of the rising sun.

    1. Re:nobody talks about the actual problems? by cpeikert · · Score: 3, Interesting

      well after 69 comments (hehe), there has not been a SINGLE one discussing the competition problems, all three of which are quite interesting.

      I'll take a shot.

      Ironically, I find the "easiest" one the hardest. I can think of a brute-force O(n^4) algorithm, but it's not pretty.

      The medium problem seems to be straight-up dynamic programming.

      Sadly, the "hard" problem is also straight-up dynamic programming, and is well-known. It's very lame that they chose this problem -- I'm pretty sure it's in CLR (Cormen, Leiserson, Rivest "Introduction to Algorithms"), and it's definitely considered in many other sources.

      Overall, these questions don't seem to be testing for breadth of knowledge, or even ability to think creatively. They all have essentially cookie-cutter answers.

      Coding up correct answers under time pressure is another matter, of course. I give all the credit in the world to someone who can crank out the code and test out all the corner cases properly.

    2. Re:nobody talks about the actual problems? by cpeikert · · Score: 3, Insightful

      Summarizing your algorithm: for every pair of nodes that are not connected, do the proper intersections of their in/out-neighborhoods. (Note however that the pair of nodes in the other corners must be checked for connectedness too.)

      "For every pair" => O(n^2)
      "intersect neighborhoods" => O(n log n)
      (by sorting the entries in the neighborhoods and comparing from there)
      But as for checking connectedness of pairs in the two intersections, that's again O(n^2).

      So we're back at O(n^4) (not to mention the work that goes into preventing double-counting of cycles that are found in several different ways).

      Which solution would you rather code up? :)

  12. competition paradigm by lingqi · · Score: 4, Insightful
    I personally think this is a better programming competition paradigm than TopCoder.

    in case people will probably not bother to click, it goes something like this:

    you have three days to do the programming task (72 hours), and you submit it via email. you can use whatever language you want, etc etc. here is an official quote:

    Programming should be about correctness and elegance, not about writing something in a hurry. Correctness is more and more important, for example in life-support systems and drive-by-wire automobiles, where there is no room for error.

    There is no room for error in this contest either. The first thing the judges will do is test the programs and eliminate any entry that does not give correct results on all tests. Besides, the task will be simple enough that 3 days will be enough time to write, debug, and do some tweaking on your program, and get a normal amount of sleep. It was already the case for the previous years, and we see no reason to change.

    the cool thing is this
    [for the 1st place] Finally, the contest judges agree to state at least once during the presentation of the awards that the winning team's programming language is "the programming tool of choice for discriminating hackers."

    [for 2nd place] The contest judges agree to state at least once during the presentation of the awards that the winning team's programming language is "a fine programming tool for many applications."

    [for special judges prize] The contest judges agree to state at least once during the presentation of the awards that the winning team is comprised of a group of "extremely cool hackers."

    anyway... the money isn't as good, but I like it much better. btw the winner for the 2001 one used haskell, and second place used Dylan, ha! eat my (shorts), Arthur. =)
    --

    My life in the land of the rising sun.

  13. Re:good thing by ErroneousBee · · Score: 5, Insightful
    hehe you must have scored REALLY bad on the competitions to have this kind of attitude.

    I did a 'sort of' competition thing (it was actually a study in how programmers program), and I found that the problem was nothing like what I meet in the real world:

    • The spec was really watertight, not 'Uh, make it show birthdays, and, uh, see if the users like it'.
    • There were no OSINTOTs or other gotchas like broken APIs or liscencing issues.
    • The spec didnt change halfway through the task.
    • No-one dumped a completely unrelated, but more urgent, task in my lap just as I was about to start coding.
    • QA didnt suddenly start bitching about a feature thats been in the product for years, but theyve only just noticed, and no-one uses anyway.
    • The problem was chosen for its elegant recursive solution. Most of my real world problems are solved by a tiny bit of iteration and masses of conditional logic/exception handling dealing with all the dumb things the user/system can get up to.

    In general, I suspect these competitions reflect academic computing, producing nice and small programs. The real world is more like Google's pagerank software, a simple idea, but complicated by all sorts of issues like Bloggs and Googlebombers.

    --
    **TODO** Steal someone elses sig.
  14. Fascinating reading by Anonymous Coward · · Score: 5, Insightful

    I don't normally read SlashDot, but after a friend pointed out this post to me, I had to check it out. Having done so, I couldn't resist making a couple comments.

    "I find it interesting that a math double-major, who's considering becoming a math professor, uses C++"

    I don't see much use for computer programming at all in mathematics, except in applied areas that don't interest me. I learned C++ because it was ideal for game programming, and I learned Java because it was taught in college and used at the company where I worked.

    "Maybe there is some kind of speed math problem think tank that secretly controls the world around us"

    Amazingly enough, it is actually possible for certain people to do more than one thing, including math research and contests. For example, I once met this guy who could walk and talk at - get this - the same time. It was pretty crazy.

    "With looks like those... it's no surprise he has nothing better to do."

    Yeah, screw you too. At least I have better things to do than flame college students on SlashDot. In fact, I spend no more than two hours a week on TopCoder, often less. I almost never practice, and I have not competed very many times.

    "someone who won top coder is saying it's a good indication of real world ability"

    I believe I said that it is not completely irrelevant. That would be different. Since I did this interview for some internet thing that neither I nor my friends read, and since I am not even looking for a job right now, I didn't really have a vested interest.

    "(tenured math professor = job security)"
    "he's smart enough to know even he can't get a job programming"

    If you guys think it is easier to get and maintain a good programming job than it is to get and maintain a math professorship at, say, Harvard, you are very much mistaken.

    "So this guy is telling us he makes this for the money and he will become a math professor?"

    I believe I mentioned that money is no longer my primary reason for doing TopCoder. Furthermore, just because I choose to spend minimal time making lots of money given the opportunity, does not mean I can't live with a bad-paying job.

    "normally you do not *decide* to become a professor"

    Really? I actually think this is precisely what happens.

    "other serious, more difficult, competitions like the ACM"

    You don't know what you're talking about. Everybody in the TopCoder top 10 has done extremely well on some or all of the ACM, the IOI, the Putnam, and the IMO. Of these contests, I'd say the ACM is actually the most worthless (straightforward problems, missing constraints, ridiculous 3-person 1-computer dynamic, ridiculous 2-year limit).

    "Mr. TopCoder could very easily be a pro athlete. He sure answers questions like one."

    What do you want me to say? Maybe I should have answered questions like "Have you thought about how you want to apply your computer skills after graduation?" with "Actually, since I'm a super-genius, I thought I would show P != NP, and then maybe move on to the Riemann hypothesis, and then maybe I'd see if I could fly just by thinking really hard, like that dude in the Matrix". Certain questions will get lame answers every time.

    To those of you who aren't asses, good day.

    -- David Arthur