doreshnikov's blog

By doreshnikov, history, 4 weeks ago, In English

1579A - Casimir's String Solitaire

Idea: MikeMirzayanov

Tutorial
Solution

1579B - Shifting Sort

Idea: doreshnikov

Tutorial
Solution

1579C - Ticks

Idea: MikeMirzayanov

Tutorial
Solution

1579D - Productive Meeting

Idea: doreshnikov

Tutorial
Solution

1579E1 - Permutation Minimization by Deque

Idea: MikeMirzayanov

Tutorial
Solution

1579E2 - Array Optimization by Deque

Idea: doreshnikov

Tutorial
Solution

1579F - Array Stabilization (AND version)

Idea: doreshnikov

Tutorial
Solution

1579G - Minimal Coverage

Idea: doreshnikov, MikeMirzayanov

Tutorial
Solution

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By doreshnikov, history, 4 weeks ago, translation, In English

Hello Codeforces!

Sorry for a bit delayed English announcement, we are glad to invite you all to Codeforces Round #744 (Div. 3), third division round held on Sep/28/2021 17:35 (Moscow time). This round was prepared by me and MikeMirzayanov and we hope that you'll find the problems interesting and enjoy solving them.

I would like to thank MikeMirzayanov for helping me with both writing and preparing the problems for this round. Since it's the second Div. 3 round held I'm involved in but only the first one I'm preparing problems for from zero all the way to the end, without his guidance it would've taken much more of my time.

Also special thanks to nizamoff, andreumat, QAZZY, Vladosiya, CtrlAlt, vladmart, Igorjan94, okwedook, I_Remember_Olya_ashmelev and Aris_244_ for testing the round and giving their feedback on the problems as well as to Gassa and geranazavr555 for proofreading and correcting the statements. This round is very noticeably better than it could've been without your contribution. And last but not least, thanks to everyone who'll be participating! This round contains 7 to 8 problems and is expected to be of decent level of difficulty for participants with ratings up to 1600. However, all of you who wish to take part and have a rating 1600 or higher, can register for the round unofficially.

The round will be hosted by rules of educational rounds (extended ACM-ICPC). Thus, during the round, solutions will be judged on preliminary tests, and after the round, it will be a 12-hour phase of open hacks. We tried to make tests strong enough but it doesn't at all guarantee that open hacks phase will be pointless.

You will be given 7-8 problems and 2 hours 15 minutes to solve them.

Note that the penalty for the wrong submission in this round (and the following Div. 3 rounds) is 10 minutes.

Remember that only the trusted participants of the third division will be included in the official standings table. As it is written by link, this is a compulsory measure for combating unsporting behavior. To qualify as trusted participants of the third division, you must:

  • take part in at least two rated rounds (and solve at least one problem in each of them)
  • do not have a point of 1900 or higher in the rating.

Regardless of whether you are a trusted participant of the third division or not, if your rating is less than 1600, then the round will be rated for you.

Good luck and have fun!

UPD: Editorial is out!

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By doreshnikov, 4 months ago, translation, In English

1547A - Shortest Path with Obstacle

Idea: MikeMirzayanov

Tutorial
Solution

1547B - Alphabetical Strings

Idea: MikeMirzayanov

Tutorial
Solution

1547C - Pair Programming

Idea: geranazavr555, MikeMirzayanov

Tutorial
Solution

1547D - Co-growing Sequence

Idea: doreshnikov

Tutorial
Solution

1547E - Air Conditioners

Idea: geranazavr555, MikeMirzayanov

Tutorial
Solution

1547F - Array Stabilization (GCD version)

Idea: doreshnikov

Tutorial
Solution

1547G - How Many Paths?

Idea: MikeMirzayanov

Tutorial
Solution

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