Educational Codeforces Round 87 [Rated for Div. 2]

Revision en11, by awoo, 2020-05-20 20:34:02

Hello Codeforces!

On May/17/2020 12:20 (Moscow time) Educational Codeforces Round 87 (Rated for Div. 2) will start.

Please notice the unusual time.

Series of Educational Rounds continue being held as Harbour.Space University initiative! You can read the details about the cooperation between Harbour.Space University and Codeforces in the blog post.

This round will be rated for the participants with rating lower than 2100. It will be held on extended ICPC rules. The penalty for each incorrect submission until the submission with a full solution is 10 minutes. After the end of the contest you will have 12 hours to hack any solution you want. You will have access to copy any solution and test it locally.

You will be given 6 or 7 problems and 2 hours to solve them.

The problems were invented and prepared by Roman Roms Glazov, Adilbek adedalic Dalabaev, Vladimir vovuh Petrov, Ivan BledDest Androsov, Maksim Neon Mescheryakov and me. Also huge thanks to Mike MikeMirzayanov Mirzayanov for great systems Polygon and Codeforces.

Also thanks to Neal neal Wu for testing.

Good luck to all the participants!

Our friends at Harbour.Space also have a message for you:

Codeforces and Harbour.Space

Hi Codeforces!

We would like to invite you to a very special webinar called Digital Lockdown: AI against COVID-19, by Sergey Gordeychik, director of our Cyber Security programme.

Sergey is CIO of Inception Institute of Artificial Intelligence, and former CTO at Kaspersky.

During this webinar, Sergey will share his expertise and insights on how AI is being used both positively and negatively, during the COVID-19 global pandemic. Tune in for some practical examples of how companies are using AI to innovate and disrupt during a time of crisis, exploring topics like Medical Imaging for CT analysis, diagnosis and mass surveillance.

Join us on Thursday, May 28th at 12h (BCN) to gain knowledge and deepen your understanding about how we can use AI to solve both operational and societal problems.

By participating in this 1hour webinar you will get a certificate of participation, a special digital gift from Sergey, and have the chance to win a FREE 3-week module at Harbour.Space University, depending on the availability and prerequisites of the course.

Reserve your spot now!

Congratulations to the winners:

Rank Competitor Problems Solved Penalty
1 square1001 8 294
2 Anadi 8 305
3 tfg 8 681
4 kefaa2 7 192
5 xay_naive 7 248

Congratulations to the best hackers:

Rank Competitor Hack Count
1 qwscaln 29:-2
2 Ankit 5
3 lvao-x 3:-1
4 the_redback 3:-1
5 WICK_ED 2:-1
142 successful hacks and 828 unsuccessful hacks were made in total!

And finally people who were the first to solve each problem:

Problem Competitor Penalty
A fedoseev.timofey 0:02
B Ashishgup 0:03
C1 hitman623 0:04
C2 square1001 0:15
D Not-Afraid 0:10
E autumn_eel 0:17
F squarepants 0:47
G riantkb 0:37

UPD: Editorial is out


  Rev. Lang. By When Δ Comment
en11 English awoo 2020-05-20 20:34:02 106
ru8 Russian awoo 2020-05-20 20:33:35 104
en10 English awoo 2020-05-18 13:13:36 2750
ru7 Russian awoo 2020-05-18 13:13:06 2728
en9 English awoo 2020-05-17 16:21:35 62
ru6 Russian awoo 2020-05-17 16:21:06 71
en8 English Una_Shem 2020-05-16 16:26:43 39 Tiny change: 'start.\n\nSeries' -> 'start.\n\n**Please notice the unusual time.**\n\nSeries'
ru5 Russian Una_Shem 2020-05-16 16:22:14 2 Мелкая правка: 'аунда.**\nПродолжа' -> 'аунда.**\n\nПродолжа'
ru4 Russian Una_Shem 2020-05-16 16:21:50 80
en7 English Una_Shem 2020-05-16 16:15:04 35 Tiny change: 'ill start.**Please notice the unusual time.**\n\nSeries' -> 'ill start.\n\nSeries'
en6 English Una_Shem 2020-05-16 16:14:15 35 Tiny change: 'ill start.\n\nSeries' -> 'ill start.**Please notice the unusual time.**\n\nSeries'
en5 English Una_Shem 2020-05-16 16:11:44 0 (published)
ru3 Russian Una_Shem 2020-05-16 16:11:28 0 (опубликовано)
en4 English Una_Shem 2020-05-16 15:08:41 2 Tiny change: 'persky._\n_During ' -> 'persky._\n\n_During '
en3 English Una_Shem 2020-05-16 15:06:36 2 Tiny change: 'ty program._ \n\n_Se' -> 'ty programme._ \n\n_Se'
ru2 Russian Una_Shem 2020-05-16 15:05:33 1618
en2 English Una_Shem 2020-05-16 13:54:54 1607
en1 English awoo 2020-05-15 22:51:10 1285 Initial revision for English translation (saved to drafts)
ru1 Russian awoo 2020-05-15 22:50:13 1402 Первая редакция (сохранено в черновиках)