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Educational Codeforces Round 85 [Rated for Div. 2]

Revision en6, by awoo, 2020-04-12 12:04:22

Hello Codeforces!

On Apr/10/2020 17:35 (Moscow time) Educational Codeforces Round 85 (Rated for Div. 2) will start.

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.

Good luck to all the participants!

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

Codeforces and Harbour.Space

Hey Codeforces,

What a crazy month it’s been!

We hope you and your loved ones are taking care of one another and catching up on everything you didn’t have time for on your normal schedules.

We’ve temporarily closed our physical campus and moved our classes online. It’s not as bad as it sounds though — we’ve always known the future is digital, so we were already preparing for this moment. Either way, we’re back.


This digital transformation opens the door to some pretty awesome new opportunities that allow us to get closer to our community, no matter where in the world they are.

That’s why we have a special prize for the next Educational Round, a space in a course of your choice from our Computer Science or Data Science Programs. You’ll be able to study online with us for 1, 2 or 3 weeks under some of the best Data and Computer Scientists in the world, with all fees on us.

The prize will be for the top 3 users who have confirmed their desire to participate in this competition. To sign up for it, leave us your handle in the form below.

Enrollment in the course you will participate in will depend upon the availability of the course, as well as the prerequisites required for that course.

We hope this provides you with extra incentive for the round, and we’re looking forward to seeing some of you soon!



On a different note, we’re happy to announce that we’re offering full scholarships for the most talented high school students who want to study in our Computer Science or Data Science Bachelor’s programs at our university.

At the moment, we have two types of scholarships available:

The Full Scholarship. For the best of the best — all tuition costs are covered by the university. Just show up and show us what you’ve got.

The Co-Creator Scholarship. For those who want to help us change education — all tuition costs are covered by the university, and in addition to your studies, you get to help the Harbour.Space team on their mission for 4 hours/day, getting valuable practical experience in the field and working in a team with some of the brightest young professionals in town.

Fill out the form below and we will contact you for the next steps!


Looking forward to seeing you kick some ass in the next Educational Round, and stay safe!

Best, Harbour.Space University

Congratulations to the winners:

Rank Competitor Problems Solved Penalty
1 Retired_MiFaFaOvO 7 153
2 jiangly 7 195
3 amnesiac_dusk 7 244
4 risujiroh 7 290
5 bmerry 7 310

Congratulations to the best hackers:

Rank Competitor Hack Count
1 greencis 174:-53
2 Java 94:-8
3 hackVerly 55:-2
4 nGu 55:-10
5 TheScrasse 40
2405 successful hacks and 1303 unsuccessful hacks were made in total!

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

Problem Competitor Penalty
A IQOver20 0:02
B arknave 0:02
C Siberian 0:03
D sevlll 0:16
E LJC00118 0:19
F IceWiz 0:31
G Cirno_9baka 0:25

UPD: Editorial is out


  Rev. Lang. By When Δ Comment
en6 English awoo 2020-04-12 12:04:22 2625
ru5 Russian awoo 2020-04-12 12:03:54 2601
en5 English awoo 2020-04-11 20:49:41 70
ru4 Russian awoo 2020-04-11 20:49:00 72
ru3 Russian Una_Shem 2020-04-09 19:25:48 75
en4 English Una_Shem 2020-04-09 19:22:05 8 Tiny change: 'nd-color:#523996; color:wh' -> 'nd-color:#00796B; color:wh'
ru2 Russian Una_Shem 2020-04-09 19:19:15 3252 (опубликовано)
en3 English Una_Shem 2020-04-09 19:08:31 90
en2 English Una_Shem 2020-04-09 18:03:16 3394 (published)
en1 English awoo 2020-04-09 15:58:57 1285 Initial revision for English translation (saved to drafts)
ru1 Russian awoo 2020-04-09 15:58:13 1402 Первая редакция (сохранено в черновиках)