rng_58's blog

CODE FESTIVAL 2017 Onsite Event
By rng_58, history, 7 years ago, In English

The onsite event of CODE FESTIVAL 2017 will start soon. There will be four contests during the event:

All contests will have parallel rounds. Only Final will be rated (and corresponding parallel round will be rated too).

Check the schedule of the contests at https://atcoder.jp/.

UPD: Now the final standings is available at https://beta.atcoder.jp/contests/cf17-final/standings.

Congratulations to winners:

  1. tourist
  2. ksun48
  3. Um_nik
  4. Marcin_smu
  5. ko_osaga
  • Vote: I like it
  • +99
  • Vote: I do not like it

Comments Comments (26)
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7 years ago, # |
  Vote: I like it +8 Vote: I do not like it

Will there be a grand final like last year?

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

    No, this year there will be four contests listed above.

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7 years ago, # |
  Vote: I like it -15 Vote: I do not like it

Who are the writers?

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7 years ago, # |
← Rev. 4   Vote: I like it 0 Vote: I do not like it

Schedule (Note that all time are in JST (GMT + 9)):

Saturday (25 November 2017)

CODE FESTIVAL 2017 Final (Parallel) (Rated)

Time : 12.30pm — 3.30pm (3 hours)

Scoring : 300-400-500-700-1000-1000-1000-1600-1600-1900

Link : https://cf17-final-open.contest.atcoder.jp/

CODE FESTIVAL 2017 Exhibition (Parallel)

Time : 7.40pm — 8.40pm (1 hour)

Scoring : 1000-1500

Link : https://cf17-exhibition-open.contest.atcoder.jp/

Sunday (26 November 2017)

CODE FESTIVAL 2017 Elimination Tournament Round 1 (Parallel)

Time : 10.00am — 10.30am (30 minutes)

Scoring : 700-800

Link : https://cf17-tournament-round1-open.contest.atcoder.jp/

CODE FESTIVAL 2017 Elimination Tournament Round 2 (Parallel)

Time : 10.45am — 11.15am (30 minutes)

Scoring : 700-900

Link : https://cf17-tournament-round2-open.contest.atcoder.jp/

CODE FESTIVAL 2017 Elimination Tournament Round 3 (Parallel)

Time : 11.30am — 12.10pm (40 minutes)

Scoring : 800-1000

Link : https://cf17-tournament-round3-open.contest.atcoder.jp/

Code Festival Team Relay (Parallel)

Time : 3:30pm — 5pm (1 hour 30 minutes)

Scoring : 100-100-100-100-100-100-100-100-100-100-100

Link : https://cf17-relay-open.contest.atcoder.jp/

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7 years ago, # |
  Vote: I like it +26 Vote: I do not like it

  • Is there a list of official participants somewhere?

  • I'm confused, what are these contests about? Final is usually the last round (that's what "final" means), here it's first? If the rest happens after the final, what's the point?

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    7 years ago, # ^ |
      Vote: I like it +64 Vote: I do not like it

    To have fun in so many ways

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    7 years ago, # ^ |
      Vote: I like it -6 Vote: I do not like it

    Sorry the list of participants is not publicly available now, but you will be able to see the standings during the contest.

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

Will there be a broadcast like last year? My guess is not (because parallel round), but confirm it just for know.

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

    No (last year broadcast was for grand final).

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7 years ago, # |
  Vote: I like it +29 Vote: I do not like it

Onsite competition scoreboard ?

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

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

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7 years ago, # |
  Vote: I like it +15 Vote: I do not like it

Can someone explain the solution to Problem H? I don't really get what the editorial is trying to say.

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    7 years ago, # ^ |
      Vote: I like it +20 Vote: I do not like it

    Maybe the solution from ksun48 could help you. It implements the part of "Similar transition for four directions" from the editorial in an elegant way lol.

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

How to solve CODE FESTIVAL 2017 Exhibition — Increment and Swap ?

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

    May i ask how to solve problem A-Awkward?

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

      Use inclusion-exclusion principle: for each k — number of edges we add to the answer ( - 1)k times number of ways to choose k edges denoting prohibited neighbors in the final row. Each set of these k edges adds to the sum ( - 1)k·(n - k)!·2comps, where comps is the number of connected components these k edges form. These values can be calculated with dp(vertex v, number of edges taken in its subtree, number of taken edges incident to v).

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

    We published editorial: https://cf17-exhibition-open.contest.atcoder.jp/editorial.

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7 years ago, # |
  Vote: I like it +63 Vote: I do not like it

My solution of J (which turned out to be different from model solution and all other contestant's solution)

Spoiler
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    7 years ago, # ^ |
    ← Rev. 2   Vote: I like it +21 Vote: I do not like it

    Cool solution:) I didn't come up with. (maroonrk's solution in the parallel contest was same.)

    The intended solution was O(N log N) but there is an O(N) solution (wow) by yutaka1999 as below.

    Spoiler
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7 years ago, # |
  Vote: I like it -58 Vote: I do not like it

Finally, I got the 1st place in Code Festival 2017 Relay (Parallel). Thank you for all!!!

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7 years ago, # |
  Vote: I like it +36 Vote: I do not like it

I can't read/submit any problems to "Code Festival Team Relay (Parallel)" after contest ends. (without registration in the real-time contest). Please fix this? (Or it is not a bug?)

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7 years ago, # |
  Vote: I like it +24 Vote: I do not like it

Question irrelevant to this event, but does AtCoder plans on having virtual contests? Would be great to have them

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    7 years ago, # ^ |
      Vote: I like it +3 Vote: I do not like it

    AtCoder don’t support virtual contest, but we have two options to do virtual contest of AtCoder problems:

    • Use vjudge (Link) To use this for hosting virtual contest, you have to input problem ID for choosing problems. For example, problems ID of Code Festival 2017 Final are 3602 — 3611, in order. You can know problem ID to jump the link of the submit page of desired problem, and look the link name for example of “https://cf17-final-open.contest.atcoder.jp/submit?task_id=3602#” (In this case problem ID is 3602) But in this way, it took long time for searching problem ID.
    • Use AtCoder Virtual Contest (Link) though it is easy to prepare for a virtual contest, its language is Japanese, so it’s difficult to use for people who aren’t Japanese.
    So, we can do virtual contest, but in both way it is difficult to use. Hope AtCoder will make a convenient system of virtual contest like Codeforces.
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      7 years ago, # ^ |
        Vote: I like it 0 Vote: I do not like it

      But are these virtual contests with online standings as from actual competition? It is kinda essential to have them, otherwise I could just measure my time.

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