wuhudsm's blog

By wuhudsm, 16 months ago, In English

Hello, Codeforces!

We are happy to invite you to TheForces Round #22 (Interesting-Forces), which will take place on Aug/27/2023 17:35 (Moscow time)

What is TheForces Round?

Editorial

You will have 135 minutes to solve 6 problems.

We strongly recommend you to read all problems.

The round is TheForces rated!, after the round you can find your rating changes here.

Discord Server (1000+ people)

Contests' archive

  • Vote: I like it
  • +57
  • Vote: I do not like it

| Write comment?
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16 months ago, # |
  Vote: I like it +7 Vote: I do not like it

As a tester, I can confirm that the problems are very interesting. And very enjoyable to solve.

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16 months ago, # |
  Vote: I like it +15 Vote: I do not like it

Hopefully, it would be a INTERESTING ROUND for you! We've made a lot of adjustments to make the problems better. Wish you all the best!

(plus: plz give me contribution, thx!)

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16 months ago, # |
  Vote: I like it +17 Vote: I do not like it

As an author, I'd like to thank everyone who contributed to this round, especially Yawn for testing :D

This is my first time ever to be an author :D

Couldn't have been done without my G EyadBT, special thanks to him :)

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16 months ago, # |
  Vote: I like it +9 Vote: I do not like it

thank you for the round and I hope the problems are interesting

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16 months ago, # |
  Vote: I like it +8 Vote: I do not like it

The registration is open!

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16 months ago, # |
Rev. 2   Vote: I like it 0 Vote: I do not like it

Is there any simple solution to B?

Or is it just casework like I did?

  • if n=1, then miller rabin test
  • if k even, then 0
  • check 111...222
  • check 5...evens
  • check with 3 (probably had some issues here ig)
  • check 1...222...(even)
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    16 months ago, # ^ |
      Vote: I like it +3 Vote: I do not like it

    when n=1 the concatination of k with its self will never be prime if k>1,but if k=1 it will. thats beacuse when you concatenate k with its self it will be writen like k times 10 to some power puls k and this expression is divisable by k which is greater than 1

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    16 months ago, # ^ |
      Vote: I like it 0 Vote: I do not like it