errorgorn's blog

By errorgorn, 3 years ago, In English

Hello again Codeforces 👋,

We are excited to invite you to TOKI Regular Open Contest #24!

Key details:

Many thanks to:

  • prabowo 👨‍❤️‍💋‍👨 for 🕒 coordinating the 👦🌷 contest and translating our 💰🅱 stupid 😕💩 jokes into ➡ Indonesian 🇮🇩.
  • icypiggy for helping 💻 us 🅱👍 to prepare testdata.
  • Our 💩🏽 army of 😫👩 testers dantoh, tqbfjotld, -rs-, jamessngg, iLoveIOI, pavement for testing the problems and making us delete a problem 😡🤬 giving useful feedback 🥰😇.
  • hocky for drawing beautiful diagrams 👌😍 for our problems.
  • fushar for the wonderful 🌈 TLX platform and fixing TLX after 🔜💯 we 😀👦 broke it multiple times.

Please 😩 register for 👍 the 🚪🅱 contest, and we hope you will 😘 enjoy 😋💋 the contest! Good 👌 luck 😄 have 😏😝 fun!

P.S. Please note ✏️📔 the unusual 🤪 duration 🕐⏱️🕝 I recommend 👍 not reading 🙈📖 all the problems 💀💀 to lose rating❗❗

UPD: contest is over! (no more emoji spam sadly)

Congratulations to our top 5:

  1. tourist
  2. Nyaan
  3. antontrygubO_o
  4. BigBag
  5. Itst

Congratulations to our first solvers:

Rating has been updated.

You can upsolve the problems here.

Editorial is available in the upsolve link.

Thank you for participating and see you in the next contest!

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3 years ago, # |
  Vote: I like it +27 Vote: I do not like it

😱😱😱😱

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3 years ago, # |
  Vote: I like it +58 Vote: I do not like it

Please consider adding rust to the list of available languages

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

    We have just added Rust 2021 support. Please do try it out. Looking forward to your participation!

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

      Thanks. I'll try to

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

      I am consistently getting weird compilation errors. I was able to get one submission through, but all others are CE, supposedly due to internal compiler problem. Are you sure about that linker option?

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

        We apologize for the compilation errors in Rust. Looks like we have not tested this new language thoroughly. For now, please use a different language.

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          3 years ago, # ^ |
            Vote: I like it +6 Vote: I do not like it

          I asked Snark about what commands are used to run rust in OpenCup, will get back to you with reply

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3 years ago, # |
  Vote: I like it +44 Vote: I do not like it

Screenshot-20211215-002808-Discord

"finally a TROC round"

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

What a unique TROC!!! Authors are Singaporean and there are subtasks too? WOW!!!! It isnt something you can see a lot on TROCs these days. Looking forward to joining this special contest. :)

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3 years ago, # |
  Vote: I like it +14 Vote: I do not like it

C++20 support when

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

I think the contest will clash with CF education round.

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

errorgorn Can you please try to avoid the collision between Educational round 119 and this contest by preponing or postponing this round?

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    3 years ago, # ^ |
      Vote: I like it +9 Vote: I do not like it

    yea I have talked with the edu round setters and they are willing to postpone edu round 119 :)

    so TROC 24 will remain at the same time

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      3 years ago, # ^ |
      Rev. 3   Vote: I like it -15 Vote: I do not like it

      I think the time schedule is still not very good. A 2hr contest right after another 2.30hr contest. No time for discussion.

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

The problemset is very interesting. thx

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

I guess I'll just write on how I generated the testdata for problems D and E since I think they are quite interesting. I will not write it on the editorial since prabowo will have to translate this entire chunk of text into Indonesian.

D
E

You can see the implementations here

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

for problem C , can someone explain if this greedy approach works : Taking always the leftmost 1 that minimises the resulting number of inversions or the rightmost 0 that minimises the resulting number of inversions , and in tie we take anyone.

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

    There isnt a nice way to explain why this doesnt other than providing a counter case.

    Countercase: $$$S=\texttt{101100}, K=2$$$ Changing $$$S[1]=\texttt{0}$$$ and $$$S[6]=\texttt{1}$$$ both reduced the inversion count by $$$3$$$ so according to the greedy strategy, both is fine.

    However, if we do $$$\texttt{101100} \to \texttt{001100} \to \texttt{000100}$$$ and get inversion count $$$2$$$. But the minimum inversion count is actually $$$1$$$.