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Google Code Jam – Contest scoreboard

39 points by nirvanatikku 12y ago

i0exception 12y ago
https://code.google.com/codejam/contest/2974486/dashboard https://code.google.com/codejam/contest/2974486/dashboard The questions in case anyone's interested.
prezjordan 12y ago
Had a lot of fun with this one. Seems much tougher than previous years.
- RookToH7 12y ago
  That's what I thought initially as well, but in the end I ended up solving more than last year or the year before. I felt like I wasn't going to get anything after A and B at first, though.
- pedrosorio 12y ago
  I disagree. Unlike other years, there is no "hard" problem in this round. So far, 2581 users have submitted an answer to C-large (the "hardest" this year). Last year only 547 users submitted an answer to D-large (and only 141 got the correct answer).
  - awda 12y ago
    This is just quals...
    - pedrosorio 12y ago
      "Seems much tougher than previous years." I am comparing these quals with the quals from last year.
- S4M 12y ago
  It's my first time this year, I can't understand why my answer for the mine sweeper is not correct. I think I found all the edge cases and even checked my results one by one :(
modulus1 12y ago
I'm always amazed at the speed of these guys. Top guy got it all done in an hour. I don't know if they are geniuses or if they practice this stuff every day.
- idle_processor 12y ago
  First place was taken by Gennady.Korotkevich, also known as "tourist." He has a history of placing extremely highly in sport programming contests[0], is at the top of topcoder's algorithm section[1], and has had several articles[2,3] written about him. I imagine there's a lot of practice involved, but I wasn't able to spot an interview that specified the exact amount of time tourist spends coding or studying algorithms every day. [0] http://qr.ae/vcU6j http://qr.ae/vcU6j [1] http://community.topcoder.com/tc?module=AlgoRank http://community.topcoder.com/tc?module=AlgoRank [2] http://www.wired.com/2010/11/mf_algorithmolympics/ http://www.wired.com/2010/11/mf_algorithmolympics/ [3] http://www.smh.com.au/lifestyle/the-whiz-kid-20120821-24k69.html http://www.smh.com.au/lifestyle/the-whiz-kid-20120821-24k69....
  - admp 12y ago
    There's an interview with Korotkevich dating from IOI 2009: - How many hours a day are you in front of the computer? - Not more than three to four. I like playing football and table tennis, so I try to find time for sports as well. http://www.ioi2009.org/downloads/br8-3str-en.pdf http://www.ioi2009.org/downloads/br8-3str-en.pdf
    - bouk 12y ago
      Three to four hours of practice a day is quite a lot, in comparison Johnny Ho (http://www.quora.com/TopCoder/Who-is-Johnny-Ho http://www.quora.com/TopCoder/Who-is-Johnny-Ho) only did about 1 or 2 a day while practicing for IOI 2012 Source: me asking that exact question to him at IOI 2012
      - pedrosorio 12y ago
        "Not more than three to four." != "Three or four hours practicing every day consistently" Also, this guy has been performing at an extremely high level for years. If he didn't do any competitive programming practice at all for a year, I doubt you'd notice a big difference in his performance. Some of the top guys at Topcoder Open / Google Code Jam don't even participate in matches outside of the yearly tournament and I doubt they are practicing consistently (i.e. once you get to that level at problem solving, performance doesn't seem to decay much and certainly much less than in a similar situation for athletes - though these guys are students / engineers whose brains are still being stimulated and solving other kinds of problems outside of competitions).
EToS 12y ago
Problem E: Pagination!
just2n 12y ago
So all evidence suggests that the 3rd problem is the hardest, by far, which is likely just some number of non-obvious edge cases. Curious why the "hard problem" disclaimer is on the 4th? The 4th also has a 90% solve rate (with 50% more submissions) while the 3rd has 44%.
- RookToH7 12y ago
  Yeah, that disclaimer scared me off at first. I solved D last, but in the end I do feel that it's easier than C. I suppose you can solve C-small with a more naive method though.
  - mjp94 12y ago
    Agreed. I definitely found D much easier than C. Was able to get C small after a failed attempt, but never stood a chance at getting C large.
    - pedrosorio 12y ago
      To be fair, C large has the biggest score of all subproblems.
    - RookToH7 12y ago
      The odd thing is, though, I still don't really see how you can solve C-small without solving C-large at the same time (other than actual brute-force). Guess I'll be keeping my eyes peeled for the write-up.
      - pedrosorio 12y ago
        "other than actual brute-force"
- raphaelj 12y ago
  The 4th is definitively the funniest. In addition to the disclaimer, one thing which worried me was the N <= 1000 in the large problem specification. I got a quite elegant fast solution and a so low bound was really surprising.
Noxchi 12y ago
When someone asks why not outsource the coding to India, point them to this page. The first Indian winner is #236, but if you go to the last page, there are a bunch of them trying. EDIT: I'm gonna make a script to list the best countries that output programmers.
- Aaronn 12y ago
  How about this from last year? http://www.go-hero.net/jam/13/regions http://www.go-hero.net/jam/13/regions
- thyroxo 12y ago
  I'm American, but this kind of statement pisses me off: just because some people from India didn't perform well in the Google Code Jam, we shouldn't hire them?
- dllu 12y ago
  There's not really much difference between the top 1000 places, since all that matters is solving all 4 problems. This is the qualification round that goes on for 27 hours, so there is not much pressure to solve the problems fast. The Indian programmers are in a time zone that makes it difficult to get up at 4:30am just to solve the problems a bit faster. Comparing the performance in the next few rounds would make more sense.
  - sgeisenh 12y ago
    Wait, do the results from each round make a difference in subsequent rounds? I didn't take the time to implement a solution to problem C because I felt like it would take too long.
    - dllu 12y ago
      As long as you qualify, results from each round do not make a difference in subsequent rounds. [0] [0] https://code.google.com/codejam/faq.html https://code.google.com/codejam/faq.html
- 12y ago
tonetheman 12y ago
One thing I did not like about this years problems was I never could get the minesweeper one. And I could not decide if it was my formatting or my answer. I think my answer was right though... ah well. no worries.
Oculus 12y ago
Man - that problem 3 was a pain. I couldn't get it to work until the last minute. Anyone solve the small case for problem 2, but get the large case incorrect? Can't fathom what the issue might be.
- libria 12y ago
  You can diff your output against someone else's to see if you can find a discrepancy, then debug it from there.
- socillion 12y ago
  I'd guess it's due to rounding. Agreed on C.
ipince 12y ago
Well, looks like 20,594 people made it through the qualification round. Higher than last year, when 17,054 people made it: http://www.go-hero.net/jam/13/round/0 http://www.go-hero.net/jam/13/round/0

39 points by nirvanatikku 12y ago

https://code.google.com/codejam/contest/2974486/dashboard https://code.google.com/codejam/contest/2974486/dashboard The questions in case anyone's interested.

prezjordan 12y ago

Had a lot of fun with this one. Seems much tougher than previous years.

RookToH7 12y ago
That's what I thought initially as well, but in the end I ended up solving more than last year or the year before. I felt like I wasn't going to get anything after A and B at first, though.
pedrosorio 12y ago
I disagree. Unlike other years, there is no "hard" problem in this round. So far, 2581 users have submitted an answer to C-large (the "hardest" this year). Last year only 547 users submitted an answer to D-large (and only 141 got the correct answer).
- awda 12y ago
  This is just quals...
  - pedrosorio 12y ago
    "Seems much tougher than previous years." I am comparing these quals with the quals from last year.
S4M 12y ago
It's my first time this year, I can't understand why my answer for the mine sweeper is not correct. I think I found all the edge cases and even checked my results one by one :(

modulus1 12y ago

I'm always amazed at the speed of these guys. Top guy got it all done in an hour. I don't know if they are geniuses or if they practice this stuff every day.

idle_processor 12y ago
First place was taken by Gennady.Korotkevich, also known as "tourist." He has a history of placing extremely highly in sport programming contests[0], is at the top of topcoder's algorithm section[1], and has had several articles[2,3] written about him. I imagine there's a lot of practice involved, but I wasn't able to spot an interview that specified the exact amount of time tourist spends coding or studying algorithms every day. [0] http://qr.ae/vcU6j http://qr.ae/vcU6j [1] http://community.topcoder.com/tc?module=AlgoRank http://community.topcoder.com/tc?module=AlgoRank [2] http://www.wired.com/2010/11/mf_algorithmolympics/ http://www.wired.com/2010/11/mf_algorithmolympics/ [3] http://www.smh.com.au/lifestyle/the-whiz-kid-20120821-24k69.html http://www.smh.com.au/lifestyle/the-whiz-kid-20120821-24k69....
- admp 12y ago
  There's an interview with Korotkevich dating from IOI 2009: - How many hours a day are you in front of the computer? - Not more than three to four. I like playing football and table tennis, so I try to find time for sports as well. http://www.ioi2009.org/downloads/br8-3str-en.pdf http://www.ioi2009.org/downloads/br8-3str-en.pdf
  - bouk 12y ago
    Three to four hours of practice a day is quite a lot, in comparison Johnny Ho (http://www.quora.com/TopCoder/Who-is-Johnny-Ho http://www.quora.com/TopCoder/Who-is-Johnny-Ho) only did about 1 or 2 a day while practicing for IOI 2012 Source: me asking that exact question to him at IOI 2012
    - pedrosorio 12y ago
      "Not more than three to four." != "Three or four hours practicing every day consistently" Also, this guy has been performing at an extremely high level for years. If he didn't do any competitive programming practice at all for a year, I doubt you'd notice a big difference in his performance. Some of the top guys at Topcoder Open / Google Code Jam don't even participate in matches outside of the yearly tournament and I doubt they are practicing consistently (i.e. once you get to that level at problem solving, performance doesn't seem to decay much and certainly much less than in a similar situation for athletes - though these guys are students / engineers whose brains are still being stimulated and solving other kinds of problems outside of competitions).

EToS 12y ago

Problem E: Pagination!

just2n 12y ago

So all evidence suggests that the 3rd problem is the hardest, by far, which is likely just some number of non-obvious edge cases. Curious why the "hard problem" disclaimer is on the 4th? The 4th also has a 90% solve rate (with 50% more submissions) while the 3rd has 44%.

RookToH7 12y ago
Yeah, that disclaimer scared me off at first. I solved D last, but in the end I do feel that it's easier than C. I suppose you can solve C-small with a more naive method though.
- mjp94 12y ago
  Agreed. I definitely found D much easier than C. Was able to get C small after a failed attempt, but never stood a chance at getting C large.
  - pedrosorio 12y ago
    To be fair, C large has the biggest score of all subproblems.
  - RookToH7 12y ago
    The odd thing is, though, I still don't really see how you can solve C-small without solving C-large at the same time (other than actual brute-force). Guess I'll be keeping my eyes peeled for the write-up.
    - pedrosorio 12y ago
      "other than actual brute-force"
raphaelj 12y ago
The 4th is definitively the funniest. In addition to the disclaimer, one thing which worried me was the N <= 1000 in the large problem specification. I got a quite elegant fast solution and a so low bound was really surprising.

Noxchi 12y ago

When someone asks why not outsource the coding to India, point them to this page. The first Indian winner is #236, but if you go to the last page, there are a bunch of them trying. EDIT: I'm gonna make a script to list the best countries that output programmers.

Aaronn 12y ago
How about this from last year? http://www.go-hero.net/jam/13/regions http://www.go-hero.net/jam/13/regions
thyroxo 12y ago
I'm American, but this kind of statement pisses me off: just because some people from India didn't perform well in the Google Code Jam, we shouldn't hire them?
dllu 12y ago
There's not really much difference between the top 1000 places, since all that matters is solving all 4 problems. This is the qualification round that goes on for 27 hours, so there is not much pressure to solve the problems fast. The Indian programmers are in a time zone that makes it difficult to get up at 4:30am just to solve the problems a bit faster. Comparing the performance in the next few rounds would make more sense.
- sgeisenh 12y ago
  Wait, do the results from each round make a difference in subsequent rounds? I didn't take the time to implement a solution to problem C because I felt like it would take too long.
  - dllu 12y ago
    As long as you qualify, results from each round do not make a difference in subsequent rounds. [0] [0] https://code.google.com/codejam/faq.html https://code.google.com/codejam/faq.html
12y ago

tonetheman 12y ago

One thing I did not like about this years problems was I never could get the minesweeper one. And I could not decide if it was my formatting or my answer. I think my answer was right though... ah well. no worries.

Oculus 12y ago

Man - that problem 3 was a pain. I couldn't get it to work until the last minute. Anyone solve the small case for problem 2, but get the large case incorrect? Can't fathom what the issue might be.

libria 12y ago
You can diff your output against someone else's to see if you can find a discrepancy, then debug it from there.
socillion 12y ago
I'd guess it's due to rounding. Agreed on C.

ipince 12y ago

Well, looks like 20,594 people made it through the qualification round. Higher than last year, when 17,054 people made it: http://www.go-hero.net/jam/13/round/0 http://www.go-hero.net/jam/13/round/0