Codeforces Round #273 English Editorial (C is available now!) Hello everyone. I have noticed the absence of round 273's editorial, so I decided to write one. This is the first time I write an editorial, so hope everyone like this! I didn't know how to solve C and E yet, so it would be appreciated if someone help me with these problems. Also, how to use LaTex in codeforces? I want to use this so my editorial would be more clear to read. **UDP:** Actually, there's a (well-hidden) tutorial for this round, but it's written in Russian (with a English version using google translate in comment section). If you can read Russian, [click here](http://mirror.codeforces.com/blog/entry/14307#comment-192751). **UDP2:** Problem C is now available! A — Initial Bet =============== Since the coin only pass from this player to other player, the coins sum of all player won’t change in the game. That mean, we’ll have `5*b = c1+c2+c3+c4+c5`. We’ll put `sum = c1+c2+c3+c4+c5`. So, if `sum is divisible by b`, the answer will be `sum/b`. Otherwise, the ans...

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Educational Codeforces Round 75 [Rated for Div. 2] Hello Codeforces! On [contest_time:1251] [contest:1251] will start. Series of Educational Rounds continue being held as [Harbour.Space University](https://harbour.space/) initiative! You can read the details about the cooperation between [Harbour.Space University](https://harbour.space/) and Codeforces in the <a href="http://mirror.codeforces.com/blog/entry/51208">blog post</a>. 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 **7 problems** and **2 hours** to solve them. The problems were invented and prepared by Roman [user:Roms,2019-10-23] Glazov, Adilbek [user:adedalic,2019-10-23] Dalabaev, Vladimir [user:Vovuh,2019-10-23] Petrov, Ivan [user:Bl...

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Codeforces Round #498 (Div. 3) Hello! Finally I am freed from the big part of summer cares and I can continue the preparation of Div. 3 rounds! I decided to add something written by me to this blog because [user:TryToKnowMe,2018-07-15] (and many others, i think) [noticed](https://mirror.codeforces.com/blog/entry/60377?#comment-442051) that i am really copy and paste this text from one announcement to another changing only contest name and start time. But... Who knows, may be this time which is saved by copy-pasting the announcement allows me to prepare the problems better?... Let it stay a mystery. So, let's go. [contest:1006] will start at [contest_time:1006]. You will be offered 6 problems with expected difficulties to compose an interesting competition for participants with ratings up to 1600. Probably, participants from the first division will not be at all interested by this problems. And for 1600-1899 the problems will be too easy. However, all of you who wish to take part and have rating 1600 or higher, can re...

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Educational Codeforces Round 52 [Rated for Div. 2] On [contest_time:1065] [contest:1065] will start. [cut] Series of Educational Rounds continue being held as [Harbour.Space University](https://harbour.space/) initiative! You can read the details about the cooperation between [Harbour.Space University](https://harbour.space/) and Codeforces in the <a href="http://mirror.codeforces.com/blog/entry/51208">blog post</a>. This round will be **rated for the participants with rating lower than 2100**. It will be held on extented ACM 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 **7 problems** and **2 hours** to solve them. The problems were invented and prepared by Roman [user:Ajosteen,2018-09-19] Glazov, Adilbek [user:adedalic,2018-10-11] Dalabaev, Vladimir [user:Vovuh,2018-10-11] Petrov, Ivan [user:BledD...

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Codeforces Round #273 (Div. 2) Hi, everyone! Regular Codeforces round #273 for participants from the second division will take place on [16 October, 19:30 MSK](http://www.timeanddate.com/worldclock/fixedtime.html?msg=Codeforces+Round+%23273+%28Div.+2%29&iso=20141016T2230&p1=1915&ah=2). Participants from the first division are able to participate out of the contest. Problem setter: [user:KhaustovPavel,2014-10-15] (Khaustov Pavel, Russia, Tomsk, Tomsk Polytechnic University) Special thanks to [Codeforces](http://mirror.codeforces.com) team and, in particular, Maxim Akhmedov ([user:zlobober,2014-10-15]) for help in round preparations and Maria Belova ([user:Delinur,2014-10-15]) for translations. Participants will be given five problems and two hours to solve this problems. **Points distribution: 500-1000-1500-2000-2500** **UPD: +10 minutes to start** Good luck!

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Educational Codeforces Round 34 [Rated for Div. 2] Hello Codeforces! On [December 12, 18:05 MSK](https://www.timeanddate.com/worldclock/fixedtime.html?day=12&month=12&year=2017&hour=18&min=5&sec=0&p1=166) Educational Codeforces Round 34 will start. Series of Educational Rounds continue being held as [Harbour.Space University](https://harbour.space/) initiative! You can read the details about the cooperation between [Harbour.Space University](https://harbour.space/) and Codeforces in the <a href="http://mirror.codeforces.com/blog/entry/51208">blog post</a>. This round will be **rated for Div. 2** again. It will be held on extented ACM ICPC rules. After the end of the contest you will have one day to hack any solution you want. You will have access to copy any solution and test it locally. You will be given **7 problems** and **2 hours** to solve them. The problems were prepared by Mikhail [user:PikMike,2017-11-08] Piklyaev, Ivan [user:BledDest,2017-11-22] Androsov and me. Good luck to all participants! I also have a ...

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Codeforces Global Rounds 2020: Final Results In 2020, with the support of XTX Markets, 6 rounds of the Codeforces Global Rounds were held. Each round was common for both divisions. All such rounds were rated for all participants. At each such round, 50 brand T-shirts were handed out, and we gave T-shirts to all problem writers! I say a big thank you to XTX Markets (and personally to Yuri Bedny and Alexander Gerko) for supporting Global Rounds. Without your help, we could not host them! I sincerely admire companies like these who come to support and develop the community that some of their employees come from. It will be great if other companies follow the example and also offer their help. We need it! The prizes for the 6-round series in 2020: - In each round, top-100 participants get points according to the [table](https://pastebin.com/QT5sXEaT). - The final result for each participant is equal to the sum of points he gets in the four rounds he placed the highest. - The best 20 participants over all series get...

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Codeforces Global Rounds 2019: Final Results In 2019, with the support of XTX Markets, 6 rounds of the new Codeforces Global Rounds were held. Each round was common for both divisions and had 7–9 problems. The duration of the rounds was 2-3 hours, depending on the number and complexity of the problems. All such rounds were rated for all participants. At each such round, 50 brand T-shirts were handed out, and we gave T-shirts to all authors and problem testers as well. The prizes for the 6-round series in 2019: - In each round, top-100 participants get points according to the [table](https://pastebin.com/QT5sXEaT). - The final result for each participant is equal to the sum of points he gets in the four rounds he placed the highest. - The best 20 participants over all series get sweatshirts and place certificates. Final results: [cut]<br/> | Place | Contestant | = | Round 1 | Round 2| Round 3 | Round 4 | Round 5 | Round 6 | | - | - | - | - | - | - | - | - | - | | 1 | [user:tourist,2019-12-17] | <b> 2987 </b> | ...

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Codeforces Global Rounds 2021: Current Results (GR13-GR17) In 2021 (as in 2019 and 2020), with the support of XTX Markets, 6 rounds of the new Codeforces Global Rounds are held: common rounds for both divisions of 7–9 problems each. The duration of the rounds is 2-3 hours, depending on the number and complexity of the problems. All such rounds are rated for all participants. <i>At each such round, 50 brand T-shirts are handed out, and we are happy to give T-shirts to all problem authors.</i> The prizes for the 6-round series in 2021: - In each round top-100 participants get points according to the [table](https://pastebin.com/QT5sXEaT). - The final result for each participant is equal to the sum of points he gets in the five rounds he placed the highest. - The best 20 participants over all series get sweatshirts and place certificates. Current standings after five rounds (sorted by total points in four best placed rounds): | Place | Contestant | = | GR 13 | GR 14 | GR 15 | GR 16 | GR 17| | - | - | - | - | - | - | - | - | | ...

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Codeforces Global Rounds 2021: Final Results (GR13-GR18) Tomorrow will be the first global round of this year. And we are happy to sum up the results of last season. We announce the results! We remind you that the global rounds are a joint initiative of XTX and Codeforces. We are happy to announce that they continue into the new year. We hold 6 such rounds per year. All of them are open to both divisions. At each such round, 50 brand T-shirts were handed out, and we are happy to give T-shirts to all problem authors. The prizes for the 6-round series are: - In each round top-100 participants get points according to the [table](https://pastebin.com/QT5sXEaT). - The final result for each participant is equal to the sum of points he gets in the four rounds he placed the highest. - The best 20 participants over all series get sweatshirts and place certificates. The final standings after six rounds (sorted by total points in four best placed rounds): | Place | Contestant | = | GR 13 | GR 14 | GR 15 | GR 16 | GR 17 | GR 18| |--...

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Codeforces Global Rounds 2019: Current Results After Five Rounds In 2019, with the support of XTX Markets, 6 rounds of the new Codeforces Global Rounds will be held. These will be common rounds for both divisions of 7–9 problems each. The duration of the rounds will be 2-3 hours, depending on the number and complexity of the problems. All such rounds will be rated for all participants. <i>At each such round, 50 brand T-shirts will be handed out, and we will be happy to give T-shirts to all authors and problem testers.</i> The prizes for the 6-round series in 2019: - In each round top-100 participants get points according to the [table](https://pastebin.com/QT5sXEaT). - The final result for each participant is equal to the sum of points he gets in the four rounds he placed the highest. - The best 20 participants over all series get sweatshirts and place certificates. Current standings after five rounds: | Place | Contestant | = | Round 1 | Round 2| Round 3 | Round 4 | Round 5 | | - | - | - | - | - | - | - | - | | 1 | [user:tourist,201...

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Exclaimation Mark Why isn't there an editorial for [Codeforces Round #273 (Div. 2)](http://mirror.codeforces.com/contest/478)?! For those who are able to make one.. please don't hesitate.

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Help in 478C-Table decorations I have been stuck in this problem [problem:478C] for ages now, i cannot understand the editorial (http://mirror.codeforces.com/blog/entry/18619), why does this work and also i have problem in understanding the binary search approach (https://abitofcs.blogspot.in/2014/10/a-bit-of-cf-codeforces-round-273-div-2.html), somebody please help me by providing a detailed proof!!

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First Ever Users to Reach Some Rating Milestones Revised: ratings below 1500 and greatest rises Several days ago I published a [table](https://mirror.codeforces.com/blog/entry/104320) with first people to reach certain ratings. It featured only ratings above 1500, and [user:adamant,2022-07-09] advised to do the same, but on achieving ratings below 1500. I found it quite interesting, and, after several days of collecting data about participations of 447911 Codeforces users, I finally made this table. [cut] For several reasons I firstly put another table. This is the table of greatest rating rises in the history of Codeforces. The reasons are: 1. I have collected so much data from Codeforces that it would be blasphemy not to use it in as many ways as possible. 2. These tables might intersect a lot: it's easier to get a terrific rise in ratings if you are low-rated. (Many people abuse this and deliberately get very low-rated to make a great jump.) 3. Someone recently posted a table with greatest rating rises and falls. I wasn't able to find this table to check whether it was...

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