IgorI's blog

By IgorI, history, 4 months ago, In English

Thank you for participation! Here is the editorial:

1621A - Stable Arrangement of Rooks

Editorial
Solution

1621B - Integers Shop

Editorial

1621C - Hidden Permutations

Editorial
Solution

1621D - The Winter Hike

Editorial
Solution

1621E - New School

Editorial
Solution

1621F - Strange Instructions

Editorial
Solution

1621G - Weighted Increasing Subsequences

Editorial
Solution

1621H - Trains and Airplanes

Editorial

1621I - Two Sequences

Editorial
Solution

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Tutorial of Hello 2022
 
 
 
 
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By IgorI, 5 months ago, In English

Hi, Codeforces! Happy New Year!

I'm glad to invite you to Hello 2022, which will take place on Jan/03/2022 17:35 (Moscow time). You will have $$$2$$$ hours $$$15$$$ minutes to solve the problems. This round is rated for everyone.

All problems are authored by me. I would like to thank 74TrAkToR for excellent round coordination and MikeMirzayanov for great Codeforces and Polygon.

There can be an interactive problem in this round. Don't forget to read the guide on interactive problems.

The scoring is $$$500-1000-1500-1750-2250-2750-3000-3500-4500$$$.

Good luck!

Editorial

Thank you for participation! Congratulations to the winners:

  1. tourist

  2. maroonrk

  3. Radewoosh

  4. Benq

  5. djq_fpc

  6. mnbvmar

  7. ainta

  8. mhq

  9. ecnerwala

  10. Rebelz

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Announcement of Hello 2022
 
 
 
 
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By IgorI, history, 16 months ago, In English

Thank you for participating in the contest! I hope you enjoyed the tasks. Here is an editorial with hints.

1474A - Puzzle From the Future

Hint 1
Hint 2
Editorial
Solution

1474B - Different Divisors

Hint 1
Hint 2
Hint 3
Editorial
Solution

1474C - Array Destruction

Hint 1
Hint 2
Hint 3
Hint 4
Editorial

1474D - Cleaning

Hint 1
Hint 2
Hint 3
Hint 4
Editorial
Solution

1474E - What Is It?

Hint 1
Hint 2
Hint 3
Hint 4
Editorial
Solution

1474F - 1 2 3 4 ...

Bonus
Editorial
Solution

Good luck in your future contests!

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By IgorI, history, 16 months ago, translation, In English

Hi, Codeforces!

I'm glad to invite you to take part in Codeforces Round #696, which will take place on Jan/19/2021 17:35 (Moscow time). Round will be rated for participants with rating less than $$$2100$$$. Participants from the first division can take part out of competition.

There will be $$$6$$$ problems for $$$2$$$ hours. All problems are authored by me. Thanks to adedalic for excellent round coordination and to MikeMirzayanov for Codeforces and Polygon.

Also thanks to testers errorgorn, awoo, kalki411, khiro, AmShZ, IaMaNanBord, Osama_Alkhodairy, Prakash11, Gauravvv, HIS_GRACE, Dragnoid99 for testing the round and giving valuable feedback for problems.

Scoring is $$$500-1000-1500-2000-2250-3000$$$.

Good luck!

UPD: Editorial

UPD: Congratulations to the winners!

Of both divisions:

  1. neal

  2. antontrygubO_o

  3. HIR180

  4. fuppy

  5. Thienu

Of the second division:

  1. EzioAuditoreDaFirenze

  2. Ishtar

  3. God_Of_Blunder

  4. Shivam_18

  5. AlphaAurigae

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By IgorI, history, 16 months ago, In English
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By IgorI, history, 16 months ago, translation, In English

Hello Codeforces!

Now the winter SIS (Summer Informatics School) is taking place, and parallel A+A0 and its teachers have prepared a complete Codeforces Round. You can check previous rounds, prepared by SIS students: Codeforces Round #612, Codeforces Round #530.

Codeforces Round #694 begins on Jan/05/2021 17:35 (Moscow time). In both redactions, there will be $$$6$$$ problems for $$$2$$$ hours. The round is rated for both divisions.

Problems are authored and prepared by AliceG, pakhomovee, MadProgrammer, ArtNext, fastmath, IgorI, Kapt, KhB, Hello_zoka, Karabutsa, ligaydima, Mangooste, pelmenner, Allvik06 under the guidance of meshanya, cdkrot, kokokostya, craborac, scanhex.

We would like to thank:

We recommend you to read the statements of all problems. Scoring will be announced later.

Good luck!

Scoring distribution is: $$$500 - 750 - 1000 - 1500 - 2000 - 2500$$$ in both divisions.

Editorial

System testing is over. Thank you for participating! We hope that you liked our problems!

Congratulations to the winners:

  1. tourist

  2. Petr

  3. jiangly

  4. Radewoosh

  5. ecnerwala

  6. Maksim1744

  7. lumibons

  8. Endagorion

  9. ainta

  10. DmitryGrigorev

  11. neal

All of them have solved problem E (with neal being the first). Problem F was quite challenging and no one have solved it during the contest.

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