kefaa's blog

By kefaa, 7 weeks ago, translation, In English,

Greetings from the CodeChef community!

I hope the January CookOff was a pleasant experience for all participants. To cap off this month with some more coding problems, I invite you to be a part of the year’s first lunchtime, the January Lunchtime 2018. Joining me in the problem setting panel are:

  • Problem Tester: mgch (Misha Chorniy)

  • Problem Setter: kefaa (Kirill Gulin)

  • Problem Editorialist: taran_1407(Taranpreet Singh)

  • Statement Verifier: Xellos (Jakub Safin)

  • Russian Translator: CherryTree (Sergey Kulik)

  • Mandarin Translator: huzecong (Hu Zecong)

  • Vietnamese Translator: VNOI Team

I hope you will have a great time solving them. Your feedback on the problem set is most welcome in the comments below after the contest.

Contest Details:

Time: 27th January 2018 (1930 hrs — 2230 hrs). (Indian Standard Time — +5:30 GMT) — Check your timezone.

Contest link:

Registration: You just need to have a CodeChef handle to participate. For all those, who are interested and do not have a CodeChef handle, are requested to register in order to participate.


  • Top 10 performers in Global and Indian category will get CodeChef laddus, with which the winners can claim cool CodeChef goodies. Know more here: (For those who have not yet received their previous winning, please send an email to

Good Luck! Hope to see you at the contest!

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By kefaa, 12 months ago, In English,

Today I found I can choose IOI format for my mashup (in "Edit" tab). It looks like a new feature but I can't deal with it :D.

Submitting author's solution returns the next verdict: "Partial result: 0 points"

Opening standings references me to error page:

So I thought I should set points for the problem in polygon, but I didn't find such feature. Codeforces, how to set an IOI-style contest in mashup if it possible? Or is this feature still under development?

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By kefaa, 15 months ago, translation, In English,

Hello, Codeforces community!

Codeforces Round #384 for the second division will take place on Wednesday, 14 December 17:35 MSK. Traditionally, first division participants will be able to take part out of competition.

Round was prepared by Yury hloya_ygrt Shilyaev and me, Kirill kefaa Gulin.

Many thanks to Nikolay KAN Kalinin for his help with the contest preparation and Mike MikeMirzayanov Mirzayanov for the Codeforces and Polygon systems.

You will be offered 5 problems and 2 hours for solving them.

Scoring will be announced closer to the beginning of the round.

UPD: Scoring is 500 — 1000 — 1250 — 2000 — 2500

UPD2. The contest is over! Hope you enjoyed it :)


Congratulations to the winners!


  1. TheBartender

  2. OMGIncredible

  3. lesskreker

  4. xyt520

  5. SpinyAnteater

  6. y32M-71693993

  7. Medded

  8. tqyaaaaaaaang

  9. Fiks_warrior

  10. 00001


  1. Um_nik

  2. kmjp

  3. Temirulan

  4. zscoder

  5. rajat1603

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