Codeforces Round #415 Hello everyone! This Saturday [May 20, 21:05 MSK](https://www.timeanddate.com/worldclock/fixedtime.html?day=20&month=5&year=2017&hour=21&min=05&sec=0&p1=166) rated Codeforces Round #415 takes place. As for our previous round 384, the problems were set by Kiril [user:kefaa,2017-05-16] Gulin and Yura [user:hloya_ygrt,2017-05-16] Shilyaev. And this time Daniil [user:Melnik,2017-05-16] Melnichenko joined us! Many thanks to coordinator Alex [user:netman,2017-05-16] Vistyazh for help in preparations of the round, and also to Mike [user:MikeMirzayanov,2017-05-16] Mirzayanov for Codeforces and Polygon systems. While everyone is waiting for second half of "SKAM" series season, we offer you to solve problems, main characters of which would be stunning girl Noora and well-known to you from [problem:794F] hacker Leha! As always, participants of both divisions will be given 5 problems and 2 hours to solve them. Scoring will be announced before the round. We hope you'll like our round...

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Educational Codeforces Round 91 [Rated for Div. 2] Hello Codeforces! On [contest_time:1380] [contest:1380] 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 **6 or 7 problems** and **2 hours** to solve them. The problems were invented and prepared by Roman [user:Roms,2020-07-11] Glazov, Adilbek [user:adedalic,2020-07-11] Dalabaev, Vladimir [user:vovuh,2020-07-11] Petrov, Ivan [us...

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VK Cup Round 2 + неофициальная интернет-трансляция <img src="http://assets.codeforces.com/images/vkcup2015/round_2.jpg" style="width: 40%; height: 40%; float:right; margin: 0 1em 1em 1em;" /> В [пятницу, 17-го апреля, в 19:00](http://timeanddate.com/worldclock/fixedtime.html?day=17&month=4&year=2015&hour=19&min=0&sec=0&p1=166) начнётся Раунд 2 чемпионата по программированию VK Cup 2015! Не забудьте зарегистрировать вашу команду на раунд, регистрация закроется за пять минут до его старта. В этом раунде могут принять участие все те команды, которые отобрались в Раунде 1 или в Уайлд-кард раунде 1. Напомним, что из первого раунда допущены все те команды, что набрали не менее 796 баллов. В уайлд-кард раунде было достаточно решить не менее шести задач, либо решить пять задач со штрафным временем не более 415 минут. Таким образом, принять участие в Раунде 2 могут 400 + 50 = 450 команд! Участников ждет соревнование по правилам классических раундов Codeforces. По сравнению с Раундом 1 вас ждут некоторые изменения. Во-первых, одновремен...

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Codeforces Round #422 (Div. 2) Hello everyone! This Sunday [July 2, 19:05 MSK](https://www.timeanddate.com/worldclock/fixedtime.html?day=2&month=7&year=2017&hour=19&min=05&sec=0&p1=166) rated Codeforces Round #422 (Div. 2) will be held. This time I'm the only one author in contradistinction to the Round 415. Many thanks to coordinator Alex [user:netman,2017-06-30] Vistyazh for help in preparations of the round, Vladislav [user:winger,2017-06-30] Isenbaev, Alex [user:AlexFetisov,2017-06-30] Fetisov, Nikolay [user:KAN,2017-06-30] Kalinin and Ildar [user:gainullin.ildar,2017-06-30] Gainullin for testing the problems and also to Mike [user:MikeMirzayanov,2017-06-30] Mirzayanov for Codeforces and Polygon platforms. As in the Round 415, the main characters of the tasks will be the stunning girl Noora and hacker Leha. Participants will be given six problems and two hours to solve them. As always, participants from the first division can take part out of competition. Scoring will be announced before the round. ...

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Codeforces Round #240 Statistics [contest:414] and [contest:415] round statistics [cut] : ### Div. 1 #### First accepted: **A** (00:04) [user:Zlobober,2014-04-06]<br/> **B** (00:04) [user:izban,2014-04-06] [user:klamathix,2014-04-06]<br/> **C** (00:28) [user:WJMZBMR,2014-04-06]<br/> **D** (00:25) [user:mochavic,2014-04-06]<br/> **E** (01:56) [user:sankear,2014-04-06]<br/> #### Total hack attempts: +18:-62 #### Top-9 hackers: **150** [user:gskhirtladze,2014-04-06] +3:-3<br/> **150** [user:naagi,2014-04-06] +2:-1<br/> **100** [user:TankEngineer,2014-04-06] +1:-0<br/> **100** [user:Gassa,2014-04-06] +1:-0<br/> **100** [user:JuanMata,2014-04-06] +1:-0<br/> **100** [user:waltz7I9,2014-04-06] +1:-0<br/> **100** [user:Bugman,2014-04-06] +1:-0<br/> **100** [user:BigBag,2014-04-06] +1:-0<br/> **100** [user:louise,2014-04-06] +1:-0<br/> #### Other info <br/> [Complete Div. 1 Results](https:...

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Codeforces Round #415 Editorial [tutorial: 810A] <spoiler summary="Setter's code"> ~~~~~ int n, k, s = 0; cin >> n >> k; for (int i = 0; i < n; ++i) { int x; cin >> x; s += x; } for (int ans = 0;; ans++) { int a = 2 * (s + ans * k); int b = (2 * k - 1) * (ans + n); if (a >= b) { cout << ans; return 0; } } ~~~~~ </spoiler> First accepted [user:Zhigan,2017-05-21]. [tutorial: 810B] <spoiler summary="Setter's code"> ~~~~~ for (int i = 0; i < n; i++) { cin >> k[i] >> l[i]; a.push_back(make_pair(min(2 * k[i], l[i]) - min(k[i], l[i]), i)); } sort(a.rbegin(), a.rend()); long long ans = 0; for (int i = 0; i < f; i++) { int pos = a[i].second; ans += min(2 * k[pos], l[pos]); } for (int i = f; i < n; i++) { int pos = a[i].second; ans += min(k[pos], l[pos]); } cout << ans; ~~~~~ </spoiler> First accepted [user:polygonia,2017-05-21]. [tutorial: 809A] <spoiler summary="Setter's code"> ~~~~~ st[0] ...

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Daily Diary (Competitive Coding in Summers) I realised that there is only one way improve one's skill, and that is through practice. So I decided to practice more topics and more problems on codeforces and different judges. This is simply a daily record for what I did through my vacation. I also want to tell you about **stopstalk.com** . It is a good site to make and keep you daily coding record. ##**16 MAY 2017** ##### **Problems Solved** - ###### 1. http://mirror.codeforces.com/problemset/problem/535/D This was a simple problem and it used Z function for prefix length calculation ###### **solution link** &mdash; http://mirror.codeforces.com/contest/535/submission/27152004 ###### 2. http://mirror.codeforces.com/problemset/problem/551/B Although the problem was simple, I had some trouble in understanding the language of the problem. It took time more than required. ###### **solution link** &mdash; http://mirror.codeforces.com/contest/551/submission/27160921 <br> ##### **Participated Contest** - I participated in a v...

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Codeforces Round #415 Conflicts With TCO17 Algorithm Round 2A The recently announced Codeforces Round #415 is at a time which directly overlaps with TCO17 Algorithm Round 2A. Given that the TCO schedule was announced a while ago could the Codeforces round possibly be moved?

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Is the performance of Arrays.sort quadratic here? In the problem Div 2 C of the recent Codeforces round #415, I got TLE on test 69. I was unable to figure out the reason as the loop was running for just n times. So, I changed my array to arraylist, and used `Collections.sort()` instead of the `Arrays.sort()`. To my surprise, it passed without any other changes! What could be the reason here? Check my last 2 submissions for this : [TLE Submission](http://mirror.codeforces.com/contest/810/submission/27253597) and [Accepted submission](http://mirror.codeforces.com/contest/810/submission/27253938)

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Contest materials component missing There is a component in the bottom right of every contest page with the heading "Contest materials". However, this component seems to be missing from the contest page of round #415 (both div 1 and 2). [Link](http://mirror.codeforces.com/contest/810/). Is it just me or this a bug?

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Codeforces Round #240 (Div. 2) D Hi everyone :) can anyone tell me why my code gives right answer for the first 4 test and it doesnt give the correct answer for the 5th one . i would really really appreciate your help :) PS : i think my algorithm is correct thats why i dont want to read sb else's code :) thanks :) http://mirror.codeforces.com/contest/415/submission/11136797

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Weird bug with pow? I had a weird WA during Round #300 ([B](http://mirror.codeforces.com/contest/538/submission/10878173)) for the test case `415`. I used the custom invocation tool and realized that `((int) pow(10, i))` when `i=2` is equal to 99 and the `number` becomes `100` instead of `101`. On my machine, the same code passed.

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Teams going to Gwalior/Pune Regionals **UPDATE:** I've uploaded the code that I used to generate this on Github, in case someone needs to generate something similar: [Codeforces Team Rating Calculator](https://github.com/abdullah768/Codeforces-Team-Rating-Calculator) The regional round has ended and here's the final Ranklist: https://www.codechef.com/public/rankings/ACM18GWR Inspired by the list of teams going to Kharagpur regionals, I decided to make one for Gwalior/Pune regionals. The list contains all the teams from the official Gwalior website. If you know the usernames of members of any of the teams. Please update the excel file: ### [HERE] (https://docs.google.com/spreadsheets/d/1jRvwzQzp1DOcazgI7jXBB8uY3u7Ze_eQ77Xa75_Q810/edit?usp=sharing) Team rating calculation has been done according to the official Codeforces team rating calculation formula. The table will be updated with details from the excel file every 6 hours or so. Last Updated: 10 pm, 12th December IST | No. | AIR | Team Name ...

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Problem on 810B, Codeforces Round 415(Div. 2) Hey, I'm relatively new to competitive programming, does anyone know what I did wrong here? http://mirror.codeforces.com/contest/810/submission/27251228 Thanks in advance

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