Zlobober's blog

Google Code Jam Round 2
By Zlobober, 12 years ago, translation, In English

GCJ Round 2 starts today at 14:00 UTC. It's a good chance to take cool T-Shirt, just place 1000 or higher. Top 500 contestants will advance to Round 3.

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12 years ago, # |
  Vote: I like it +16 Vote: I do not like it

Did anyone else sort for B and then forget to reverse it before doing the output? Because... I did.

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    12 years ago, # ^ |
      Vote: I like it +5 Vote: I do not like it

    I did it to, and I got 2 WA because of it... And then 1 more WA because of mistake in reversing.

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    12 years ago, # ^ |
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    Yes!!) I thought that I am the only one) It cost me 2 tries...

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    12 years ago, # ^ |
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    I did :) But I've found it before downloading large test

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    12 years ago, # ^ |
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    Ya, 2 incorrect submissions for me, too :(

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    12 years ago, # ^ |
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    I did! 3 penalties + 20 minutes wasted because of that! Would have been in top-500 otherwise :(

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    12 years ago, # ^ |
    ← Rev. 2   Vote: I like it 0 Vote: I do not like it

    I remembered to reverse before printing the output but I forgot to sort before processing :D

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12 years ago, # |
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It seems that everyone got D-large wrong. Is there a bug in the testdata, or is the testdata extremely tricky?

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    12 years ago, # ^ |
      Vote: I like it +11 Vote: I do not like it

    Probably no one knows how to solve it properly so they tried some heuristics which didn't work.

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12 years ago, # |
  Vote: I like it +12 Vote: I do not like it

Contest Analysis

http://code.google.com/codejam/contest/1842485/dashboard#s=a&a=4

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12 years ago, # |
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In problem B, once we fail enough attempts to say it isn't possible to add the current circle, should we start all over again or backtrack to when we added the previours circle?

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    12 years ago, # ^ |
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    Backtracking works. I try 20 different locations then go back to the previous circle.

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    12 years ago, # ^ |
    ← Rev. 6   Vote: I like it +5 Vote: I do not like it

    As stated in the analysis, we always have at least 20% chance to succeed. So the probability to fail x times is 0.8^x, which decreases rapidly. I also tried a solution without backtracking and it worked very fast. It means we only need to repeat the randomize progress until finding a consistent point. (you may take a look at tourist's code)

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12 years ago, # |
  Vote: I like it +1 Vote: I do not like it

Is there someone who get T-shirts?

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