rng_58's blog

CODE FESTIVAL 2016 Qualification Round C
By rng_58, history, 8 years ago, In English

CODE FESTIVAL 2016 Qualification Round C will be held on Sunday Monday (time). The writer is sigma425.

Contest Link

Contest Announcement

This is one of the three qualification rounds of CODE FESTIVAL. Top 5 foreign students of this round will qualify. If you are eligible for the onsite contest, please don't forget to fill the form at https://krs.bz/rhd-itm/m/code_fes_2016. Please check the detail of the tournament at http://codeforces.net/blog/entry/46647.

The contest duration is 2 hours, and there will be 5 problems. The first 4 problems are mainly used for choosing domestic students and much easier than other tournament competitions. However, we added one more problem and we hope this is interesting enough for choosing top 5 qualifiers. (Anyway, most probably the qualifiers will be determined by the speed of solving all problems). Note that there is no time penalty for incorrect submissions. The time penalty is MAX, not SUM.

The point values are 100 — 200 — 400 — 800 — 1200. If you are unfamiliar with AtCoder System, 2X-point problem in AtCoder is as hard as TopCoder's d1 X-point problem.

Let's discuss problems after the contest.

UPD: Fixed the date.

UPD: The top 5 were jcvb, W4yneb0t, riadwaw, xyz111, and xyz2606. Congratulations!

UPD: Since wwwwodddd turned out to be a cheater, this account was excluded from the contest and banned from AtCoder. The qualifiers and the ratings were recomputed.

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8 years ago, # |
  Vote: I like it 0 Vote: I do not like it

Auto comment: topic has been updated by rng_58 (previous revision, new revision, compare).

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8 years ago, # |
  Vote: I like it 0 Vote: I do not like it

Auto comment: topic has been updated by rng_58 (previous revision, new revision, compare).

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8 years ago, # |
  Vote: I like it +42 Vote: I do not like it

How did wwwwodddd solve the complete set so fast (the first submission for E was just 3 minutes after getting AC of D, and 36 minutes from the beginning)? Was the last problem used before?

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    8 years ago, # ^ |
    ← Rev. 3   Vote: I like it +30 Vote: I do not like it

    This 396D - On Sum of Number of Inversions in Permutations can be solved using similar ideas.

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      8 years ago, # ^ |
        Vote: I like it +33 Vote: I do not like it

      And how does it help? I solved E today, I'm absolutely sure I could not rewrite it in 8 minutes. Does he have the same solution as everyone else?

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        8 years ago, # ^ |
          Vote: I like it +10 Vote: I do not like it

        You can view his code: http://code-festival-2016-qualc.contest.atcoder.jp/submissions/945001

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        8 years ago, # ^ |
          Vote: I like it +10 Vote: I do not like it

        I mean if you know how to solve similar problem, you can came up with right idea very quickly and need only to think about implementation, which is much more easier. It took me approximately 15 minutes today to invent the solution for E, 10 to implement and 3 to debug.

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          8 years ago, # ^ |
            Vote: I like it +94 Vote: I do not like it

          I'm talking about the case when you already wrote the solution several hours ago. I still can't write it not even in three minutes, but in even bigger time. I still need to write formulas.

          I looked at his solutions of D and E, and they seem pretty different to me:

          0) mentioned before -- three minutes after D.

          1) one of them has return 0, other -- doesn't.

          2) one of them has bits/stdc++.h, other -- different includes.

          3) one of them has space before every ; other -- doesn't.

          Etc.

          http://code-festival-2016-qualc.contest.atcoder.jp/submissions/945001

          http://code-festival-2016-qualc.contest.atcoder.jp/submissions/944562

          It seems weird to me. Well, E could be copypasted from somewhere, then this all is understandable.

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            8 years ago, # ^ |
              Vote: I like it +28 Vote: I do not like it

            It seems you are implying that this person might be multiple people.

            If someone wanted to cheat like that, and they were smart enough to solve all the problems, wouldn't they also be smart enough to make it slightly less obvious?

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              8 years ago, # ^ |
                Vote: I like it +31 Vote: I do not like it

              Before reading this thread, I didn't know it was possible to view others' solutions. Maybe he didn't know that either.

              Looking at all his codes, I find it quite suspicious that solutions to B,C,D follow almost the same coding style while solution to E is completely different and solution to A is in python.

              I don't want to make any claim here, because it might be very unfair if everything turns out ok, but I think it would be a good idea if the organizers check that (e.g. see if the submissions are from the same computer).

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8 years ago, # |
  Vote: I like it +43 Vote: I do not like it

Auto comment: topic has been updated by rng_58 (previous revision, new revision, compare).

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8 years ago, # |
  Vote: I like it 0 Vote: I do not like it

I'm just wondering if wwwwodddd on Codeforces and wwwwodddd on AtCoder are the same person.

Since the account has been banned, I can't compare his codes on these contest systems.

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