Codeforces Round #603 (Div. 2) Привет Codeforces! Мы, [user:Supermagzzz,2019-11-28], [user:Stepavly,2019-11-28], [user:AdvancerMan,2019-11-28], [user:unreal.eugene,2019-11-28], студенты ИТМО, желая внести свой вклад в развитие сообщества Codeforces, обратились к [user:MikeMirzayanov,2019-11-28] с предложением помочь с тестированием новых раундов. Но [user:MikeMirzayanov,2019-11-28] предложил нам свою помощь в разработке собственного раунда. Поэтому... Мы рады пригласить вас на [Codeforces Round #603 (Div. 2)](http://codeforces.me/contest/1263), который пройдет в [contest_time:1263]. Он будет рейтинговым для **всех участников, чей рейтинг ниже 2100**. Вам будет предложено **шесть задач** и **два часа** на их решение. Задачи были придуманы и подготовлены [user:Supermagzzz,2019-11-28], [user:Stepavly,2019-11-28], [user:AdvancerMan,2019-11-28], [user:unreal.eugene,2019-11-28], [user:MikeMirzayanov,2019-11-28]. Особую благодарность выражаем: - [user:VArtem,2019-11-28], [user:Nebuchadnezzar,2019-11-28...

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The most outrageous cheating in the history of Huawei Challenge  I am writing this because I believe that prohibited collaboration occurred during this Challenge and affected the prize positions. To state my personal conclusion plainly: I believe this is cheating, not merely a collection of innocent coincidences. The final positions relevant to the accounts discussed in this post were: | Rank | Handle | Final score | Result of my public-data review | |---:|---|---:|---| | 2 | [user:IceKylin,2026-08-28] | 16808.628 | Historical team with [user:candy0014,2026-08-28] named “IceKylin 0339 team”; all-time runtime/score leads with [user:candy0014,2026-08-28] and [user:Retired_Zhisheng,2026-08-28] | | 3 | [user:mahiro_zcy,2026-08-28] | 16757.390 | Repeated all-time runtime/score correlation with [user:mojo__hugo,2026-08-28]; repeated timing correlation with [user:Zinc-acetate,2026-08-28]; weak close event with [user:Mango2011,2026-08-28] | | 4 | [user:Zinc-acetate,2026-08-...

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Maintaining mst with online edge insertions — no LCT needed This blog is about maintaining mst with online edge insertions (or msf &mdash; minimum spanning forest to be exact) by using a data structure I came up with in $O(\log n)$ for edge insertion. although this problem can solved quite easily for anyone who knows LCT (link-cut tree), coding LCT is not really practical and has really bad constants. The data structure I present has very good constants because as you'll see all it does is manipulation on arrays. For obvious reasons that will be shown later I have called this data structure "weighted DSU". **Warmup problem** ================== The problem is stated as follows: you are given an undirected graph where each edge has a time $t_i$. you are asked to answer queries of the form "what is the smallest time t such that you can get between u and v with all edges in time $<= t$". This problem is analogous to calculating the msf of the graph where the weights are the times and being able to answer what is the maximum on the simple path ...

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Codeforces Round #334 Editorial Problem 0: Richard has been infected with bovine spongiform encephalopathy. Help Kevin understand what he's saying! [Div 2 A](http://codeforces.me/contest/604/problem/A) ------------------------------------------------------ **Hint:** Just do it! But if you're having trouble, try doing your computations using only integers. This problem is straightforward implementation---just code what's described in the problem statement. However, floating point error is one place where you can trip up. Avoid it by rounding (adding $0.5$ before casting to int), or by doing all calculations with integers. The latter is possible since $250$ always divides the maximum point value of a problem. Thus when we rewrite our formula for score as $\max\left(3\cdot x/10, \left(250-m\right)\cdot x/250\right)$, it is easy to check that we only have integers as intermediate values. **Code:** http://codeforces.me/contest/604/submission/14608458 [Div 2 B](http://codeforces.me/contest/604/problem/B...

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IQ is Pure COPE, Here's Why (Useful CP and Life Information #5?) Background ------------------ On CF I think you can tend to see people attributing good rating to IQ. This is often associated with hopelessness when people are stuck in gray/green. I think it's the perfect cope &mdash; it's the easiest thing to say that completely explains why you're 1100 and your friend is orange, and, bonus, if anyone tries to prove you wrong, you can just claim that they are privileged and intelligent. You may think I am 2000 and thus out of touch to be able to comment on this topic, which _may_ be true. However, I was also once a noob who got 28/1000 on a USACO silver round. And I was pretty overweight as a kid and sucked at sports and always thought of myself as not having the genetics to be an athlete, but [I now hold the squat, bench, and deadlift 18-and-under state records in my powerlifting federation](https://pa.liftingdatabase.com/records-default?recordtypeid=72&categoryid=603&weightclassid=5). (Probably not for long though lol) A lot of this i...

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TopCoder SRM 603 [6 Jan 2014, 20:00 MSK](http://www.timeanddate.com/worldclock/fixedtime.html?&day=06&month=01&year=2014&hour=11&min=00&sec=0&p1=179)

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JBOI 2015 problem Startup. Hi everyone. Can somebody please help me to solve [**this**](http://mendo.mk/Task.do?id=603) problem. Thank you very much. It is from JBOI 2015, it's called Startup.

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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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Denial of judgement error on codeforces Hey guys, when I submitted a solution to problem (603A-Alternative Thinking) , an error occurred called Denial of judgement . So, what is Denial of Judgement error and why is it occurring? Can someone enlighten me on this issue? Here the link to my solution-http://codeforces.me/contest/603/submission/35550623

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Which compiler is better, PyPy 3 or Python 3 ? Codeforces say PyPy 3 runs faster mostly but here it is a different case I was solving a problem [Secret Passwords](https://codeforces.me/contest/1263/problem/D) from Round 603. When I submitted the solution [submission:66044015] to the PyPy 3 compiler, it got TLE on test case 4 but the same solution [submission:66043555] passes in Python 3. So why does PyPy 3 solution got TLE ?? Can anyone help me with this ?

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First Ever Users to Reach Some Rating Milestones Hi there! Recently after [contest:1696] [user:Um_nik,2022-06-29] [noticed](https://t.me/umnik_team_eng/2201) that he might be the ninth or tenth person to reach <b>3600</b> rating points, but still he did it earlier than [user:Petr,2022-06-29]. I wondered whether [user:Um_nik,2022-06-29] really was <i>that</i> attentive to know for sure how many people reached <b>3600</b> before him. As this is an objective truth or an objective misconception, I decided to simply check it. [cut] After several hours of programming and abusing Codeforces API I am ready to state that [user:Um_nik,2022-06-29] was indeed correct — he and [user:jiangly,2022-06-29] both broke through the <b>3600</b> mark simultaneously, being the ninth and tenth person to achieve it. I wanted to get more interesting facts from the fetched information — for example, although [user:Petr,2022-06-29]'s maximum is <b>3597</b> and he hasn't got to <b>3600</b> so far, he was the second one to get to <b>3550</b> points, and ...

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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://codeforces.me/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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Milestones: ratings below 1500 and greatest rises (2024 edition) <i>Note.</i> This is an updated version of [this post](https://codeforces.me/blog/entry/104683). If you like [this style](https://codeforces.me/blog/entry/104320) more, please tell me in the comments. Since [user:tourist,2024-09-05]'s [breakthrough](https://codeforces.me/blog/entry/133401), I've received a lot of requests to update my old posts with rating achievements. However, I wasn't able to do it immediately since my method of doing it requires to download the rating change history of every user, which, in turn, requires to perform several hundred thousand requests to Codeforces, about which the website (and Cloudflare) is not happy. It took more that three days, but finally the job is done! Below are two tables. The first one is the greatest positive rating changes. The second one is the first users ever to reach some rating value. [cut] <table> <tr> <th>Place</th> <th>&Delta;</th> <th>Person</th> </tr> <tr> <td>1^st</td> <td><b>1182<...

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Milestones: ratings above 1500 and greatest falls (2024 edition) <i>Note.</i> This is an updated version of [this post](https://codeforces.me/blog/entry/104681). If you like [this style](https://codeforces.me/blog/entry/104320) more, please tell me in the comments. Since [user:tourist,2024-09-05]'s [breakthrough](https://codeforces.me/blog/entry/133401), I've received a lot of requests to update my old posts with rating achievements. However, I wasn't able to do it immediately since my method of doing it requires to download the rating change history of every user, which, in turn, requires to perform several hundred thousand requests to Codeforces, about which the website (and Cloudflare) is not happy. It took more that three days, but finally the job is done! Below are two tables. The first one is the greatest (by absolute value) negative rating changes. The second one is the first users ever to reach some rating value. [cut] First table: <spoiler> <table> <tr> <th>Place</th> <th>&Delta;</th> <th>Person</th> </tr> ...

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First Ever Users to Reach Some Rating Milestones Revised: ratings above 1500 and greatest falls Several days ago I published a [table](https://codeforces.me/blog/entry/104320) with first people to reach certain ratings. It was a bit raw because, firstly, it was based on top 20000 Codeforces users by rating, and, secondly, because it only gave information about ratings divisible by 50. Now I have prepared a table that is of more complex design, but both issues are resolved. Good luck understanding what is going on in it. [cut] For several reasons I firstly put another table. This is the table of greatest rating falls 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 fall in ratings if you are high-rated. 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 right, but if someone finds it, you're welcome to pu...

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