Goodbye A2 Online Judge :( I'm sadly announcing that [a2oj.com](https://a2oj.com/) ([A2 Online Judge](https://www.facebook.com/A2OnlineJudge/)) will be retiring by end of 2019, I'll shut it down at midnight on New Year's Eve. It was something I took care of for about 10 years. I'm really sorry, but I prefer not to explain my reasons, so please don't ask me why I'm doing this, it was hard enough for me to make this decision, and also please don't try to convince me to change my mind. I'd like to say thank you to everyone who used it, and please accept my sincere apologies for shutting it down. If you have something good to say about A2OJ (how you used it or how it helped you in any way), I'd love to read that, please send it to the following email (or in a comment here): [email protected] Also please feel free to take a copy of any data you can access, and if you need some data in a specific format, please send your request to the following email: [email protected] (if the data isn't public, make sure to send f...

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Codeforces: Results of 2023 [Annual Report] Hello, Codeforces. Let's recall 2023, shall we? In this post, I want to summarize this year. You know, a lot of terrible things happen in the world, and personally, this year was the hardest and most sorrowful for me. But today, we'll remember something else. We'll remember what this year was like for Codeforces. Recently, Codeforces turned 14 years old. Not bad, right? And for many years now, when asked "What is Codeforces?" the first thing I say is — it's a community! [cut]<br/> #### Personal Thanks! On behalf of the community (and myself), I say thank you to everyone who tries, helps, and makes efforts to keep the community alive. Thank you to the developers! Although I continue to engage in development and other technical activities, I'm glad that these guys made an effort and improved the platform: [user:geranazavr555,2024-02-04], [user:unreal.eugene,2024-02-04], [user:vbandurin,2024-02-04], [user:ChurakovaAlexandra,2024-02-04], [user:medvezhonokok,2024-02-04]...

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Codeforces: Results of 2020 [Annual Report] Hi Codeforces! Yes, I know it's already April. Time flies so fast lately! Exactly a year ago we were just learning all the "delights" of lockdown. So let's remember this 2020! What was it like? I don't know about you, but we had a hell of a lot of work. I will now show you some graphs and you will be very surprised. Lockdown effect? Of course, but we did our best too. Many thanks to everyone who did not stand aside! In 2020, we celebrated our 10th anniversary and crowdfunding money helps us grow and move forward. You helped us and each other. Thank you. <a href="https://codeforces.me/10years/supporters">Thank you for your contribution!</a> We've been working hard all year to make this community a better place. Did it work out? It's up to you to judge. Many thanks to everyone who invested time and effort: * [user:geranazavr555,2021-04-09], [user:kuviman,2021-04-09], [user:cannor147,2021-04-09] helped a lot with development and new features; * [user:Una_Shem,2021-...

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Rockethon 2015 Announcement <a href="http://rocketfuel.com/"><img src="http://assets.codeforces.com/images/rockethon/HZ-LOGO-TAG-RGB-big.png" style="float:right;margin:0 2em 2em 2em;"/></a> Hello Codeforces community, I am happy to announce that [Rocket Fuel Inc.](http://rocketfuel.com/) will be hosting a Rockethon competition again! The contest is prepared by Rocket Fuel employees Eldar Bogdanov, Anton Lomonos, Lasha Lakirbaia, Alexander Ruff, Nikhil Goyal and me, Ievgen Soboliev. We hope everyone will find some interesting problems in the contest and everyone will have as much fun solving these problems as we had preparing them. Just like last year, the best participants will receive valuable prizes and top performers will get Rockethon 2015 T-shirts! Also, Rocket Fuel is interested in hiring people after this event, so please fill out the simple form during registration. About Rocket Fuel --------------------- Rocket Fuel is building technology platform to do automatic targeting and optimization of a...

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Codeforces: Results of 2013 Hello! Do you feel the breath of New Year? <img src="http://assets.codeforces.com/images/tree.png" style="float:right;margin: 0 1em 1em 1em;"/> The clock shows a day before New Year, so it is time to sum up the past. I do not have speech-writers for words in the style of "what recently seemed almost impossible, it becomes a fact of life" so I'll be short. Thank you all! Your unfading interest and constant help inspire Codeforces team for new achievements! Brilliant writers, invisible soldiers: testers, tireless and greedy for knowledge participants &mdash; all of you help Codeforces do better! I've dug into the records and made a partial list of the most notable major improvements of 2013. Some large improvements of our infrastructure are not in the list, as the community can not see them directly. * A simple way to add contest from [Polygon](https://polygon.codeforces.com/) to Codeforces::Gym. * Drafts embedded in text form fields in Codeforces and Polygon. * Multipl...

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On Div2ABs 2 years ago, [user:antontrygubO_o,2022-04-27] wrote [a blog](https://codeforces.me/blog/entry/75163) about div2ABs where he expressed his opinions that d2ABs should not be about "here is a statement, please implement what is written there". Thanks to him, the quality of d2ABs (and problem quality in general) have certainly improved. However, I still believe that there still quite large differences between how coordinators/problemsetters view d2ABs and how the intended participants view them. From the survey made by [user:kpw29,2022-04-27], we can see that most people agree that most people agree that we should **primarily** consider the target audience when proposing a task. I too think if a task is boring to div 1 contestants, we should not think of that as a reason to immediately disqualify a problem from being a d2A.  I think when people judge the interesting-ness of d2As, they try...

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Improved Codeforces Extension : CF Analytics Hello delta hunters!! I forked and added few features to the popular [CF Analytics Extension](https://github.com/ApoorvaRajBhadani/cf-analytics). You can review it here : [CF Analytics: Ashray's Fork](https://github.com/Ashrayyy/cf-analytics). Below are the main features, that I personally really wanted, and are implemented. - The extension can reproduce graph of problems solved overall, problems solved during contest and problems solved after contest separately. ###### Note: Problems solved during virtual contests will be considered Solved during contest. <table> <tr> <td width="50%"> <img src="https://github.com/Ashrayyy/cf-analytics/assets/101005702/431e8aa4-0a56-45b5-a692-2eb0e57acf44" width="100%" /> </td> <td width="50%"> <img src="https://github.com/Ashrayyy/cf-analytics/assets/101005702/302e5826-867e-48f3-b68c-f600c773e1bb" width="100%" /> </td> </tr> </table> - Now, you can click on the graphs to generate a l...

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2026 Codeforces Rating Distribution With Advanced Analytics! Hello, Codeforces ! I'm excited to share my first contribution to the community: a complete analysis of Codeforces rating distributions, as the last one I know about is [this one from 2024](https://codeforces.me/blog/entry/126802). After several days of collecting and processing data through the Codeforces API, I built a set of analytics covering user rating brackets, average time needed to reach specific rating milestones, and other interesting insights about progression on the platform. I’m also looking to build a community around future projects, learning programming, and helping each other improve. No matter your current rank on Codeforces, you’re welcome to join our newly created [Discord server](https://discord.gg/9RJHWfYUw9) ! Now let's get started with the data. I collected information only for users who have participated in at least 6 contests. I also categorized them based on their recent activity: 6 months, 1 year, 3 years, and all time. If interested in what s...

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Educational Codeforces Round 134 [Rated for Div. 2] Hello Codeforces! On [contest_time:1721] [contest:1721] 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://codeforces.me/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 Adilbek [user:adedalic,2022-08-26] Dalabaev, Vladimir [user:vovuh,2022-08-26] Petrov, Ivan [user:BledDest,2022-08-26] Androsov, Mak...

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Ethflow Round 1 (Codeforces Round 1001, Div. 1 + Div. 2) Hi Codeforces! As the Chinese New Year approaches, we are glad to invite you to our Codeforces Round [contest:2062] which will be held on [contest_time:2062]. You will be presented with $8$ problems, one of which is divided into two subtasks, and $2.5$ hours to solve them. This round will be rated for all participants. This round is the first Div. 1 + Div. 2 round on Codeforces with a four-digit round number, and it is also my first round. We hope you will enjoy this round. Great thanks to: - [user:SSerxhs,2025-01-23] for helping me prepare most problems, - [user:Yakumo_Ran,2025-01-23] for providing some problems, - [user:TheScrasse,2025-01-23] for good coordination of this round, - [user:alexdat2000,2025-01-23] for translating all statements to Russian, - [user:jqdai0815,2025-01-23], [user:ugly2333,2025-01-23], [user:dXqwq,2025-01-23], [user:Sugar_fan,2025-01-23], [user:propane,2025-01-23], [user:LuCpp,2025-01-23], [user:triple__a,2025-01-23], [user:PinkieRabbit,20...

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8VC Venture Cup Announcement <img src="http://assets.codeforces.com/images/8vc/8vc-venturecup-logo.png" style="float:right;margin:0 1em 1em 1em"/> Hey Codeforces! I’ve worked with Addepar and the broader 8 | family of companies in Silicon Valley throughout 2014 and 2015, and it’s been an excellent experience. I would encourage everyone in the community to learn more about the great work that these companies are doing and I’m happy to announce that 8 | Partners will be hosting the 8 | VC VentureCup on Codeforces! It’ll be a fun contest and I’ve worked on the problems along with a few competitive programmers in our network. The contest will begin on February 13 and consist of two rounds. ##### ABOUT 8 | PARTNERS <a href="http://eight.vc/">8 | Partners</a>, which consists of Joe Lonsdale (co-founder of Palantir) and his core team from Formation | 8, is a Silicon Valley venture capital firm that invests in industry-transforming technology companies. The team's investment portfolio includes companies suc...

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Codeforces: итоги 2012-го года С наступающим Новым Годом! На часах без пары дней Новый Год – самое время подвести итоги уходящего года. Если говорить коротко, то год для проекта оказался очень продуктивным. На Codeforces были проведены крупные чемпионаты, раунды следовали один за одним, был запущен подпроект Codeforces::Тренировки, были сделаны многочисленные улучшения/исправления/нововведения. Вот короткий список наших свершений: <img src="http://assets.codeforces.com/2012/2012-codeforces-google-trends.png" style="float:right;margin:0 1em 1em 1em;"/> - учет авторитета при голосовании за комментарии/посты, fraud detection эвристики - открытие и множественные улучшения проекта Codeforces::Тренировки - внедрен Codeforces Markup на базе Markdown со вспомогательными тегами Codeforces - на платформе Codeforces совместно с ВКонтакте был проведен очень масштабный чемпионат VK Cup 2012, около 6000 участников! - на платформе Codeforces компания КРОК провела Открытый чемпионат Москвы и Московской области по прогр...

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Educational Codeforces Round 143 [Rated for Div. 2] Hello Codeforces! On [contest_time:1795] [contest:1795] 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://codeforces.me/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 Adilbek [user:adedalic,2023-02-15] Dalabaev, Vladimir [user:vovuh,2023-02-15] Petrov, Ivan [user:BledDest,2023-02-15] Androsov, Ma...

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Yandex Cup 2024! Hello Codeforces!
 ------------ We are delighted to invite you to participate in Yandex Cup 2024!
Yandex Cup is a championship in six different tracks: - [Algorithm](https://yandex.com/cup/algorithm/)❤️ - [Backend](https://yandex.com/cup/backend/) - [Analytics](https://yandex.com/cup/analytics/) - [Mobile development](https://yandex.com/cup/mobile/) (iOS and Android tracks) - [Frontend](https://yandex.com/cup/frontend/) - [Machine Learning](https://yandex.com/cup/ml/) (Self-Driving Cars and Music information retrieval tracks) This year, as a pilot project, we are inviting schoolchildren (so far only from Russia) to participate in the Algorithm and Analytics tracks.
 The championship consists of three stages. Schedule ------------  The stages and dates are different for Machine Learning and Mobile Development. More details about the terms and conditions can be found on the track's pages. ...

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A WhatsApp Bot for Codeforces Analytics, Visualizations, and More Hello Codeforces community, ------------------ I wanted to share a useful WhatsApp-based AI assistant that might help with our competitive programming workflows. The idea is to bring essential tools directly into your chat, saving the time you'd spend switching between different websites. One of the most interesting features is its ability to generate a "true performance" graph for any user, which visualizes your performance rating in every contest. How to Use ------------------ Click the link to open a chat: [Whatsapp Chat Link](https://puch.ai/mcp/ycGISc7uVo) Send the pre-filled message that appears. The bot will then be active and you can start sending commands. Available Tools ------------------ Here is a list of its few functionalities. You can ask for them in natural language (e.g., "plot my rating graph" or "recommend a problem for me"). ###Analytics & Information `get_codeforces_user_stats`: Fetches detailed stats for one or more users. `recommend_problems`:...

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Yandex Cup 2025! Hello Codeforces!
 ------------ We are pleased to announce the start of the Yandex Cup 2025 Championship!  This year, we still have 6 tracks and a prize fund of 12 million rubles: - [Algorithm](https://yandex.com/cup/algorithm/)❤️ - [Machine Learning](https://yandex.com/cup/ml/) - [Backend](https://yandex.com/cup/backend/) - [Analytics](https://yandex.com/cup/analytics/) - [Frontend](https://yandex.com/cup/frontend/) - [Mobile development](https://yandex.com/cup/mobile/) <center style="margin: 2em;"> <a href="https://yandex.ru/cup/?utm_source=partners&utm_medium=social&utm_campaign=yandex-cup25&utm_term=CodeForces" style="text-decoration: none;font-size: 18.0px;background-color: rgb(255, 232, 28);color: rgb(0, 0, 0);font-weight: bold;padding: 0.5em 1.0em;">REGISTER</a> </center> Let's talk in more detail about two directions: **Algorithm** ❤️ An important change this year: we ask a...

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Northern Eurasia Finals 2020: Offline <img src="/predownloaded/c0/fe/c0fe3f2c5397274930f617ee822bdaecd5966927.jpg" align="right" style="height: 255px; margin: 10px;" alt="text"/> Hello everyone! After all online qualifiers, we are pleased to announce that the **Northern Eurasia Finals** and ICPC 2021 semi-final offline stage will take place this weekend on **April 3-4**! <a href="https://youtu.be/65oO4Zauvgc" style="font-size: 15.0px;padding: 8.0px 14.0px;background-color: rgb(240, 170, 10);color: white;">ICPCLive broadcast</a> <a href="http://nerc.itmo.ru/archive/2020/standings.html" style="font-size: 15.0px;padding: 8.0px 14.0px;background-color: rgb(76, 131, 195);color: white;">Standings</a> <a href="https://codeforces.me/contests/1510" style="font-size: 15.0px;padding: 8.0px 14.0px;background-color: rgb(76, 131, 195);color: white;">Mirror</a> <a href="http://nerc.itmo.ru/archive/2020/problems.pdf" style="font-size: 15.0px;padding: 8.0px 14.0px;background-color: rgb(76, 131, 195);color: white;">Problems</...

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ACM ICPC World Finals Stream Hi, everybody. We would like you to join Live broadcast from ACM ICPC World Finals 2016. The broadcast will start at [8-00 ICT 19 May 2016](http://www.timeanddate.com/worldclock/fixedtime.html?msg=Dress+Rehearsal+Broadcast&iso=20160519T08&p1=1230&ah=7), while the contest will start at [9-30 ICT](http://www.timeanddate.com/worldclock/fixedtime.html?msg=Dress+Rehearsal+Broadcast&iso=20160518T0930&p1=1230&ah=7). get more statistics afterwards. The broadcast consists of two parts: - Main broadcast with comments from our analytic [user:Egor,2016-05-17]. There will be presented all information about the contest, interviews and other interesting videos! Broadcast will be available in [youtube](https://www.youtube.com/watch?v=kIbgLrquTx4) and [twitch](http://twitch.tv/icpclive1). - Additional broadcast with videos from teams screens and web-cameras. This year you can influence what teams will be shown. For that, you should send the tweet in twitter, which contains #ICPC2016 and h...

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Яндекс.Алгоритм возвращается! Всем привет! Рады сообщить, что Алгоритм возвращается в рамках чемпионата по программированию компании Яндекс — [Yandex Cup](https://yandex.ru/cup/?utm_source=cf&utm_medium=article&utm_campaign=start17). Алгоритм — отличная возможность порешать интересные задачи, посоревноваться с участниками со всего мира и возможность выиграть денежные призы. Чемпионат в этом году пройдет полностью онлайн. Расписание: - Пробный тур начнется [21 сентября в 12:00](https://www.timeanddate.com/worldclock/fixedtime.html?iso=20200921T12&p1=166) и закончится [18 октября в 23:59](https://www.timeanddate.com/worldclock/fixedtime.html?iso=20201018T2359&p1=166) - Квалификационный раунд стартует [19 октября 2020 года в 12:00](https://www.timeanddate.com/worldclock/fixedtime.html?iso=20201019T12&p1=166), а завершится [25 октября 2020 года в 23:59](https://www.timeanddate.com/worldclock/fixedtime.html?iso=20201025T2359&p1=166). Он будет организован как виртуальный контест. В треке Алгоритм участнико...

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Codeforces Advanced Analytics Hey all! I am excited to share that we have built some advanced analytics specifically designed for your Codeforces profile. We've been working on this, and I couldn't wait to show you what we've created. It is packed with insights that will help you understand your competitive programming journey better than ever before. Here are just a few of the many features we've included: **Problem Solving Mastery** – This shows how well-equipped you are with different skills and gives you a confidence score compared to your actual rating. **Skill Growth** – Track your growth with respect to your rating, implemented using a sophisticated algorithm for calculating these metrics. **Comparing Profiles** – Compare your journey, status, win rate, and much more against another competitive programmer. (This feature currently requires authentication, but we'll soon remove that requirement as well.) And there's much more you'll discover! **Check it out here:** [MyCpTrainer](http://mycptrain...

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CF Analytics Pro, because the numbers don't lie, they just don't talk. Hi Codeforces, Like many of you, I spend a lot of time on Codeforces but I have always felt the profile page tells you *what* you solved, not *how* you solve. After a few months of looking at my own submissions manually (rating distribution, weak tags, unsolved problems), I decided to automate the parts I kept checking by hand. I also added two small quality-of-life features along the way: one-click bookmarks on any problem, and auto-fill on the submit page. The result is **CF Analytics Pro** a small browser extension that adds analytics to any Codeforces profile. [cut] <br> #### What kept bothering me Four small frustrations pushed me to build this: - Codeforces shows a flat "problem count" per tag, but not where the unsolved ones actually are. - There is no easy way to see "what should I practice next?" you have to filter the problemset manually. - Bookmarking is buried in the "Add to favourites" flow. - You finish a problem, click submit, and then realize you...

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TeamsCode Spring 2025 Virtual Programming Contest **UPD: The problems from the contest are available for upsolving at these links: [Novice Division Gym](https://codeforces.me/gym/105819) and [Advanced Division Gym](https://codeforces.me/gym/105818).** **UPD 2: The editorial for the contest can be found at [this link](https://codeforces.me/blog/entry/141840).** Hello Codeforces! [TeamsCode](http://teamscode.org) is excited to announce the [TeamsCode Spring 2025 Virtual Programming Contest](https://www.teamscode.org/contests/spring-2025)! It will take place on [**Saturday, April 05 from 11:00 AM to 5:30 PM Pacific Time / 2:00 PM to 8:30 PM Eastern Time**](https://www.timeanddate.com/worldclock/fixedtime.html?msg=TeamsCode+Spring+2025+Online+Programming+Contest&iso=20250405T11&p1=283&ah=6&am=30). **Teams of up to 4 members will have 3 hours to solve 12 problems.** There are two divisions: Novice and Advanced, so no matter what skill level you are, there is a place for you. The guest speaker event will feature Ion Barbus, a...

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Приглашаем на Алгоритм 2021! Всем привет! Рады сообщить, что очередной Алгоритм пройдет в рамках чемпионата по программированию компании Яндекс — [Yandex Cup 2021](https://yandex.ru/cup/?utm_source=cf&utm_medium=article&utm_campaign=start02). Алгоритм — отличная возможность порешать интересные задачи, посоревноваться с участниками со всего мира и возможность выиграть денежные призы. Чемпионат в этом году пройдет полностью онлайн. Расписание: - Пробный тур начнется [20 сентября в 12:00](https://www.timeanddate.com/worldclock/fixedtime.html?iso=20210920T12&p1=166) и закончится [26 сентября в 23:59](https://www.timeanddate.com/worldclock/fixedtime.html?iso=20210926T2359&p1=166) - Квалификационный раунд стартует [27 сентября 2021 года в 12:00](https://www.timeanddate.com/worldclock/fixedtime.html?iso=20210927T12&p1=166), а завершится [3 октября 2021 года в 23:59](https://www.timeanddate.com/worldclock/fixedtime.html?iso=2021103T2359&p1=166). Он будет организован как виртуальный контест. - Финал сост...

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e-maxx-eng/cp-algorithms update + free shirts from Hacktoberfest 2018 I hope most of you know your project [**e-maxx-eng**](https://cp-algorithms.com/). If you heard about it the first time: there is this really awesome Russian website ([link](http://e-maxx.ru/algo/)) about algorithms used in competitive programming by [user:e-maxx,2018-10-02]. **e-maxx-eng** is a community project that translates the material, so that competitive coder from all around the world can read and learn from the incredible useful and detailed source. Currently we have a pretty good and huge number of articles about algorithms, data structure, their implementation, lots of applications and general useful tips. Here's a quick updates on what we achieved in the last year: * There are translations available to over 100 articles (about 71% of all articles). Last year it was only about 45%. * We published a couple of original articles (e.g. about the [Sqrt Tree](https://cp-algorithms.com/data_structures/sqrt-tree.html), [Convex hull trick and Li Chao tree](https://cp-algorith...

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Chrome/Firefox Extension to analyse Codeforces profiles ### Hello coders!! Recently I have developed a chrome extension which analyses codeforces profiles and presents the chart/data on the profile webpage itself. Just open any profile on Codeforces after installing this extension. [**Install Now for Google Chrome**](https://chrome.google.com/webstore/detail/hhljbjodjdbjbggddjaidojnlmaobcpo) [**Install Now for Mozilla Firefox**](https://addons.mozilla.org/en-US/firefox/addon/cf-analytics/) Also, you can find the source code on [Github](https://github.com/ApoorvaRajBhadani/cf-analytics). The chart includes &mdash; 1. Problem rating chart &mdash; Bar chart for the number of problems solved for each problem rating 2. Tags chart &mdash; Doughnut chart for the number of problems solved for each tag across all problems 3. Unsolved problems &mdash; Gives the count and also lists all unsolved problems. Extension in action:  The UI blends easily wi...

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Codeforces Visulaizer Hello cool coders! This is my first post on CF. This is to share a small tool I built using the codeforces api. Give it a try here: [http://cfviz.netlify.com](http://cfviz.netlify.com/). The source is available [here](https://github.com/sjsakib/cfviz). Please let me know if you found any bug or issue. Current features are: Single User Analytics --------------------- - Verdicts chart - Languages chart - Tags chart - Levels chart - Total tried problems count - Total solved problems count - Average and max attempts - Count of problems solved with one submission - Max AC for a single problem (It indicates in how many ways someone solved a problem) - List of unsolved problems Comparison between two users ---------------------------- - Current, max and min rating - Number of contests - Best and worst position in contest - Max positive and negative rating change - Compared rating time-line - Total tried problem count compared - Tot...

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Grakn Forces 2020 “Codeforces… assemble!” <center> <img alt="grakn" src="https://grakn.ai/assets/svg/logo.svg" style="float:right; height: 50px; margin: 10px; max-width:10%;"/> </center> We are thrilled to announce **Grakn Forces 2020**; hosted by Codeforces and sponsored by [Grakn Labs](https://vaticle.com/). Thank you to Codeforces for providing a world-class competition structure to partner with. We can’t wait to see what you all are capable of. This international competition consists of 1 round, lasting 2.5 hours. The contest will comprise 7-9 problems and will be in accordance with classic Codeforces rules. **Prizes:** - 1st place = 500 euros - 2nd place = 250 euros - 3rd place = 100 euros **Additional Prizes:** Top 50 receive: _Grakn Labs swag pack:_ - Stickers - Grakn Labs t-shirt Random 50 from 51-250 receive: _Grakn Labs swag pack:_ - Stickers - Grakn Labs t-shirt **About Grakn Labs** [Grakn Labs](https://github.com/graknlabs) is a team...

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Stop Tab-Switching: Real-Time Audio Verdict Announcer & Advanced Analytics Dashboard Hello Codeforces! During high-profile contests (like typical Div. 2 or Div. 3 or Div. 4 rounds) where tens of thousands of participants are competing simultaneously, the judge queue often gets heavily congested. We’ve all been there: you submit a solution, and then you find yourself repeatedly smashing F5 or constantly switching tabs between your IDE and the status queue just to check if your solution passed or got a dreaded TLE/WA. Every time you switch tabs, you lose deep logical concentration, waste critical seconds, and risk racking up heavy time-decay penalties. To solve this, I built CP-Monitor — a lightweight, real-time performance dashboard and verdict announcer designed to keep your focus exactly where it matters: inside the problem. => What it does CP-Monitor connects directly to live platform queues to track your submissions. The moment the judge processes your code, it automatically broadcasts the result: Immediate Voice Announcements: It reads your submissi...

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CP-Vertex — 1v1 Duels and Weakness-Oriented Training Hi everyone! Over the past few months I've been building **CP-Vertex**, a training platform designed around one simple idea: > Most tools can tell you **what your weaknesses are**. Very few tell you **what to practice next.** The goal of CP-Vertex is to bridge that gap. Website: https://cpvertex.vercel.app/ Source Code: https://github.com/aristoncodes/CP-Vertex --- ## The Training Loop Instead of randomly picking problems, CP-Vertex follows a simple workflow: > **Analyze your profile → Identify weak topics → Practice them → Test yourself in a duel → Upsolve missed problems → Repeat** The focus is on helping you improve the topics that actually limit your progress. --- ## 1v1 Duels Challenge another programmer to a live duel. Problems are automatically selected around both players' ratings, making matches competitive rather than one-sided. Features: * Automatic problem selection * Live progress updates * Spectator mode * Server-side d...

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cp-algorithms.com update + Hacktoberfest For everybody new to [**cp-algorithms.com**](https://cp-algorithms.com/). It is a community project, that started as a translation project of the Russian algorithm website [e-maxx.ru](http://e-maxx.ru/algo). In the meantime most of the articles are translated, multiple new articles have been added, old articles have been improved and extended. In total we have 143 article about different competitive programming topics, anything from algebra, graphs, string algorithms, data structures, geometry, and more. So check it out ;-) Although in the last months not many improvements/new articles has been done (I've been busy with work/study), the website is still growing a lot. Especially last October we had a lot of new content. A year ago we had translated only 71% of the Russian articles from e-maxx.ru, today over 85% are translated. And according to Google Analytics the number of users is growing still a lot. Last year we had over 250.000 users. The following graph shows the user numbers ...

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AlgoAtlas: A New Platform for Competitive Programming Training Hello Codeforces community! I'm excited to introduce [AlgoAtlas](http://algoatlas.tech), a platform I've been developing with a standout feature that many CP enthusiasts have been asking for: a truly advanced competitive programming compiler. Key Features Advanced Code Compiler - Multi-language support including - Python - C++ - Java - C - Rust - Go - Ruby - Kotlin - Swift - PHP - TypeScript - Scala - C# - Real-time execution metrics showing time and space complexity analysis - Detailed performance metrics for your submissions - Streamlined test case management system Competitive Programming Optimized Every language comes with: - Pre-configured templates optimized for CP workflows - Proper imports/includes already set up - Main function/entry point ready to go - Standard competitive programming boilerplate C++ Template Improvements Our C++ template is now supercharged with: - bits/stdc++.h inclusion - ios::sync_with_stdio(0) and cin.tie(0) for f...

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The CodeHurdle ICPC Mock Series is Here! Hello, Codeforces! We, [user:amartya110,2026-07-16] and [user:mahesh_9996,2026-07-16], are excited to introduce the CodeHurdle ICPC Mock Series 2026. Every ICPC season, thousands of students solve random problems and participate in virtual contests. While this certainly improves problem-solving skills, the real ICPC is much more than algorithms—it's about teamwork, communication, contest strategy, and making decisions under pressure. To help teams prepare in a more structured way, we've built the CodeHurdle ICPC Mock Series, a season-long contest series designed to simulate the ICPC experience. What's Included? * 13 Structured Mock Contests * 8 Regional-Style ICPC Mocks * 5 Preliminary Contests * Hosted on Codeforces * Detailed Editorials * Video Editorials * Performance Analytics * National Rankings The objective isn't just to compete—it's to improve after every contest. **Important Dates** * Registration Opens: 15 July 2026 * Contest Begins: 2 August 2...

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Upsolve it — Stop Guessing What to Solve on Codeforces ### Hi Everyone <div style="overflow: hidden;"> <img src="/predownloaded/ea/3c/ea3ca5038d21aed7d64db88b0596f90924dd225f.png" style="float: right; width: 400px; margin-left: 25px; margin-bottom: 15px;" /> <p> If you train regularly on Codeforces, you've probably faced this. </p> <p> You open a gym<br> You see a long list of problems<br> You spend time deciding what to solve </p> <p> Is this too easy? Too hard? Even useful? </p> <p> Most people don't struggle with solving.<br> They struggle with <b>choosing what to solve</b>. </p> </div> --- #### The Idea I built **[Upsolve it](https://upsolve-it.hnuicpc.tech)**, a tool that gives you a structured way to train based on your level. * No random picking * No guessing * No wasted time before solving --- #### What It Does * **Level-based training:** reads your Codeforces rating and hands you problems at the right difficulty, hidden until the session ends. You can also adjust the level ma...

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New Extension for AtCoder Hey everyone at Codeforces!! Codeforces is a really well structured website, it is really easy to navigate to a problem and track your peers. Atcoder on the other hand, though it does has some cool features feel hollow when compared to Codeforces. It is like being surrounded by walls. So I have implemented a few features which are already present on Codeforces in AtCoder. I used Kenkoooo API to fetch rating for each problem and did get some inspiration from CF Analytics. Here are the features and the link to extension of course!! **Link for the extension:** [AC Analytics](https://chromewebstore.google.com/detail/ac-analytics/fbliobpicoanacbncphlgaghdkodkgme) Key Features 1. Activity Calander : Is added to better track your progress like in Github and Codeforces. 2. Problems Solved by Rating : See what you had been solving and up solve when needed. 3. Unsolved Problems : Easily identify and tackle unsolved problems to improve your skills. 4. Submission Histo...

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CF Custom Contests: Learn & Climb Faster (Chrome Extension) **UPD:** Thank you all for 300+ downloads in just a week! I've shipped an update with new features like analytics. Details are in [this post](https://codeforces.me/blog/entry/142919)! **TLDR:** Create custom contests instantly to efficiently train! Download on the [Chrome Web Store](https://chromewebstore.google.com/detail/codeforces-custom-contest/iafalaippdkpmfpicnhoccfbbkgnelpg?authuser=0&hl=en) Train Specific Skills & Improve Rating ================== Frustrated when problems in virtual contests jump from doable to impossible? Want to train speed or problem solving specifically? The **CF Custom Contests** extension makes this effortless! Key Features ------------------ This extension elevates your training experience by providing the following features - **Contest Settings:** Choose **problem count** & **ratings** and **contest length**. Short contest + easier problems for speed drills OR longer contest + harder problems for problem solving practice - **Contest:**...

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[Website] CF UpsolveX — Automated Upsolving Companion for Codeforces (Web App + Chrome Extension) Hello everyone! I built **CF UpsolveX**, an automated upsolving companion for Codeforces. It consists of a full-stack web application along with a Chrome extension that helps you track, prioritize, and consistently upsolve the problems you missed in contests. --- ### Problem: While participating in Codeforces contests, I often found myself saying: *"I'll upsolve the remaining problems tomorrow."* But after a few contests, dozens of unsolved problems start piling up and it becomes difficult to decide: * Which problems should be upsolved first? * Which contests still have pending problems? * How much progress has been made overall? * Whether I am actually being consistent with upsolving? Since upsolving is one of the most important aspects of improvement in competitive programming, I felt there should be a better system for tracking and prioritizing missed problems. --- ### Solution: So I built **CF UpsolveX**. It automatically tracks your missed...

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Yandex Cup 2023  #### Hi everyone, You’re invited to participate in [Yandex Cup 2023](https://yandex.com/cup/?utm_source=partner&utm_medium=site&utm_campaign=cup23&utm_content=codeforces), a programming competition run by Yandex. Our newest addition is the Algorithm track. It's a great opportunity to solve problems, compete with people from around the globe, and win cash prizes. If you're already tired of Olympiad programming problems or just looking for variety, you might want to take a closer look at the other tracks: - [Backend](https://yandex.com/cup/backend/?utm_source=partner&utm_medium=site&utm_campaign=cup23&utm_content=codeforces) and [Frontend](https://yandex.com/cup/frontend/?utm_source=partner&utm_medium=site&utm_campaign=cup23&utm_content=codeforces) Development - [Machine Learning](https://yandex.com/cup/ml/?utm_source=partner&utm_medium=site&utm_campaign=cup23&utm_content=codeforces) - [Analyti...

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Introducing cpdojo Hi Codeforces community, I have created a tool for helping out CF community &mdash; [CPDojo](https://www.cpdojo.com/). This tool can be used for monitoring ourselves and also to filter problems. Some of the features added as of now are: 1. Problems filtering based on number of solves, problems tags and ratings. Like if you need problems which are solved by atleast X people and utmost Y people, then you can filter problems that way. 2. You can also view how much problems you have solved between 2 time periods based on the problem ratings. This will help us to track exactly how many problems we solved during past 3 months and then we can make decisions based on that analytics. 3. You can also view how many problems of particular type you have solved, which will eventually contribute to your progress tracking. Sample screenshot:  I am planning to add additional functionalities too in future... If...

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CFCatalyst: Your Codeforces Training Tool ### Hey Codeforces community! Meet [CF Catalyst](https://cf-catalyst.vercel.app/), a platform to boost your contest prep with custom practice contests and smart problem selection. Whether you’re tackling Div. 2, Div. 3, or aiming higher, CFCatalyst helps you train smarter. Here’s why you’ll love it! #### What **CFCatalyst** Offers - **Custom Practice Contests:** Gear up for specific Codeforces rounds (Div. 1, Div. 2, Div. 3, Div. 4, or Educational) with custom practice contests. Our system analyzes past contests, identifies the most frequent problem tags, calculates average ratings per problem index, and generates a contest with problems within your specified min and max rating range for targeted preparation. - **Weak Topic Improvement:** Boost your skills by focusing on your weakest areas. We analyze your Codeforces submission history, pinpoint topics with the lowest success rates, and create personalized practice contests to help you master those challenging tags. - *...

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Constructor Open Cup 2026 Greetings Codeforces community! <center> <img alt="CU" src="https://codeforces.me/userpic.codeforces.org/1537714/title/5d337d6bca1a6fbc.jpg" style="float:right; height: 250px; margin: 10px; max-width:50%;"/> </center> We are excited to announce the **Constructor Open Cup 2026**, our annual online programming competition organized by Constructor University and JetBrains Foundation. **<u><font color="#008ce3">What is the Constructor Open Cup?</font></u>** Constructor Open Cup is an online contest organized by **Constructor University** and **JetBrains Foundation** to promote interest in computer science, data science, software development, and software engineering. Put your knowledge and skills to the test in this 4-hour competition and stand a chance to walk away with a scholarship for a bachelor's degree in Software, Data and Technology (BSc SDT) at Constructor University, Germany’s #1 private university*! **<u><font color="#008ce3">Constructor Open Cup timetable</...

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Are Codeforces pages sometimes rendered blank during fast browsing with Firefox? In the last few weeks or even months I've noticed that my use scenario for Codeforces became broken. Here it is: 1. Open the main page. 2. Scan "Recent actions" for interesting posts. 3. Open all of them in new tabs with mouse. 4. Go and read posts and comments. The problem is: approximately half of 5-10 opened tabs is rendered empty. Empty in the following sense: there is tab's title, one can see source HTML (e.g. the page is loaded), but the page itself is completely blank. DOM tree contains something (not too much), but `<body>`'s height is zero:  For comparison, here is the same page, rendered correctly (note that now we have several new scripts and a `<div id="body">`):  Steps to reproduce: 1. Take Firefox on Windows. My version is 52.0.2 (32 bit). I was unable to reproduce the problem in C...

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AlgoAtlas: The only CP compiler you need Hello Codeforces community! I'm excited to introduce AlgoAtlas, a platform I've been developing with a standout feature that many CP enthusiasts have been asking for: a truly advanced competitive programming compiler. Key Features Advanced Code Compiler &mdash; Multi-language support (C++, Python, Java) &mdash; Real-time execution metrics showing time and space complexity analysis &mdash; Detailed performance metrics for your submissions &mdash; Streamlined test case management system Personalized Virtual Gym &mdash; Custom contests targeting specific algorithm classes you want to improve &mdash; Adaptive difficulty progression that evolves with your skill level &mdash; Spaced repetition system to reinforce concepts at optimal intervals &mdash; Detailed level sheets to track your progression across different topics Contest Analytics &mdash; Calendar integration with major competitive programming platforms Structured Learning Paths &mdash; Expert-designed curriculum wi...

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I Was Tired of Opening 5 Tabs Every Time I Solved a Problem Hello everyone. Over the last few years, my competitive programming workflow slowly became ridiculous. A typical solving session looked something like this: - Codeforces problem page - Submit page - Custom Invocation page - VS Code - Notion / Google Docs / notebook for notes - Sometimes another tab to track progress By the time I was actually solving the problem, half my attention was already spent switching between tabs. Even worse, I kept running into the same issue: I would solve a problem, learn something useful, promise myself I'd remember it, and then completely forget it a few weeks later. A clever DP transition. A graph observation. A constructive trick. A mistake I never wanted to repeat. Everything slowly disappeared into old notebooks, random documents, or my memory. So I(Ayush) started building Leetify. Not to replace Codeforces. Just to make the workflow around solving problems feel better. Website: https://leetify-dun.ver...

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Codeforces.com according to SimilarWeb SimilarWeb is a platform for web analytics. It allows you to collect data for any sites even when you are not their owner. It is an expensive tool but some features are available for free for the start period. When I tested how it worked naturally I chose 'Codeforces.com' for my exercises:-) The very first picture surprised me.  [cut] _._ I remembered for sure that the top 5 countries with the great amount of users are India 34063 China 15750 Russia 10343 Bangladesh 8453 Egypt 3729 I counted these values by code but you can see them on RATING page. There is a table with more details as well, in free version only the first 10 rows are available:  I should admit it is my favorite diagram. I really enjoy data in the Country rank column. Isn't it coo...

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AlgoRadar: an explainable problem recommendation system for CP practice # AlgoRadar &mdash; an explainable recommender for CP practice Hello Codeforces! I built **AlgoRadar**, an open-source recommendation/analytics system for competitive programming practice. Repository: [Link](http://github.com/drawmebaaz/AlgoRadar) The goal is simple: > Given my public submission history, what should I practice next? The system uses Codeforces as the strongest source because it provides public submissions, verdicts, problem ratings, tags, rating history, and problemset metadata. It also has adapters for LeetCode and CodeChef, but Codeforces is the main difficulty anchor. --- ## 1. Main idea AlgoRadar converts public CP activity into explainable features and ranks unsolved problems by **learning value**, not just rating or popularity. Rough pipeline: ``` handle -> fetch public submissions/problem metadata -> build profile/tag/difficulty features -> classify focus areas -> estimate solve probability -> rank candidate problems -> buc...

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Leetify v0.1.2 — A Different Take on the Codeforces Problem Solving Experience Hello everyone. Before anything else, I want to make one thing clear: This project comes from a place of appreciation for Codeforces. I recently built Leetify, a browser extension that rethinks the Codeforces problem-solving workflow while trying to stay respectful of what makes Codeforces great. After talking to many users, I realized something interesting: a lot of people genuinely like the current Codeforces UI. It's familiar, lightweight, fast, and has been part of many people's competitive programming journey for years. So the goal of Leetify is not to change Codeforces. The goal is simply to make solving problems more efficient. Website: https://leetify-dun.vercel.app/ Highlights • Split-screen problem + editor workspace • Run custom tests without leaving the page • One-click submission from the workspace • Difficulty ratings and color-coded tags • VS Code-inspired editor • Notes-taking system for problems coming in v0.1.3 ...

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I built CP Compass – Analyze your Codeforces Performance # CP Compass – A Competitive Programming Analytics Platform for Codeforces Hi everyone! Over the past few months, I've been working on a project called CP Compass, a web application built specifically for Codeforces users to help them better understand their performance and identify areas for improvement. The application synchronizes your complete Codeforces history and analyzes your submissions to generate meaningful insights. It computes topic-wise statistics by grouping every solved and attempted problem according to its tags, calculates acceptance rates for each topic, and identifies your strong and weak topics based on your performance. It also analyzes problems across different rating ranges to determine your growth zone—the highest difficulty range where you're performing reasonably well and are ready to push further. Based on these insights, it recommends an unsolved problem that matches your current level and areas that need improvement. I built it to make it easie...

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I built a better CPH — and a better Codeforces while I was at it (FREE) **TL;DR -** CPH and Competitive Companion already parse samples and submit for you. CPOS does that too &mdash; but that's the boring part. The point is everything *around* it: a **browser companion** that turns the Codeforces page itself into an IDE (write and run your solution right there, plus rating-change predictions, deep profile analytics, head-to-head compare, a focus mode, and a cleaner UI), a **VS Code extension** that &mdash; unlike CPH &mdash; also renders the problem statement next to your code, and a **terminal app** that actually tells you what to solve next and how to reach your next rating. Free, open-source, MIT, and 100% local &mdash; no accounts, no servers, no tracking. - **Source (MIT):** [github.com/Soham109/cpos](https://github.com/Soham109/cpos) - **Browser companion (the good part):** [Chrome / Edge / Brave](https://chromewebstore.google.com/detail/gjnbapmjonegeeamdeahcoojgokeogmm) (Firefox source install in the repo) - **VS Code extension:** [Marketplace]...

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Educational Codeforces Round 140 [Rated for Div. 2] Hello Codeforces! On [contest_time:1767] [contest:1767] 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://codeforces.me/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 Adilbek [user:adedalic,2022-12-15] Dalabaev, Vladimir [user:vovuh,2022-12-15] Petrov, Ivan [user:BledDest,2022-12-15] Androsov, Mak...

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Any atcoder profile analyzer? I want to see my detailed profile analysis for atcoder. Mostly I need to know **how many problems I solved of which point value**. I want to see if I solve enough hard problems, or else I mostly solve only easy problems. Example counterparts for codeforces analyzer are mentioned below : Is it possible? The only thing I have found is that I can check the **number of problems solved** in atcoder using [stopstalk](https://www.stopstalk.com/user/profile/nitin12384). But it can **only display the count of problems** solved and names of the problems solved, but no other information. Is there any analyzer for atcoder that can provide more detailed info? I believe that it could be beneficial for a lot of people to be able to analyze their atcoder profile. Some examples of such analyzer tools for codeforces : A. [CF Analytics](https://chrome.google.com/webstore/detail/cf-analytics/hhljbjodjdbjbggddjaidojnlmaobcpo)  B. [Codefo...

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Чемпионат по программированию от Яндекса [Чемпионат по программированию](https://yandex.ru/championship/) — новое соревнование, проводимое компанией Яндекс. На самом деле оно не совсем новое, а является продолжением соревнования Яндекс.Блиц, которое проводилось последние [два](https://yandex.ru/promo/jobs/blitz/newhire) [года](https://yandex.ru/promo/jobs/blitz/2018/). Принять участие в чемпионате могут все граждане России, Белоруссии и Казахстана, которым уже исполнилось 18 лет. Каждый участник должен выбрать одно из четырёх соревнований: по [фронтенд-разработке](https://yandex.ru/championship/frontend/), [бэкенд-разработке](https://yandex.ru/championship/backend/), [машинному обучению](https://yandex.ru/championship/ml/) или [аналитике данных](https://yandex.ru/championship/analytics/). Победители каждого из соревнований получат призы: 1 место — 300 тысяч рублей, 2 место — 150 тысяч рублей, 3 место — 100 тысяч рублей, первые 3 — [Яндекс.Станции](https://station.yandex.ru/), первые 20 — сертификаты и футболки. Первые 20 у...

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Rockethon 2014 Overview Hello Codeforces community, I am happy to announce that Rocket Fuel Inc. will soon be hosting a contest called Rockethon on Codeforces. The contest is prepared by Rocket Fuel employees Jon Derryberry, Alexander Ruff and me, Eldar Bogdanov. We hope you will have as much fun solving the problems as we had crafting them. The contest will feature prizes and T-shirts for top performers. Also, Rocket Fuel is interested in hiring the best of you after this event, so let me tell you about the company and why you would want to join us. ### About Rocket Fuel Rocket Fuel is building technology platform to do automatic targeting and optimization of ads across all channels — display, video, mobile and social. Our pitch to advertisers is very simple "If you can measure metrics of success of your campaign, we can optimize". We have run campaigns for many large advertisers. Examples include BMW, Pizza Hut, Brooks Running Shoes and many more! We buy all our inventory through real time biddi...

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About Ethflow Hello, Codeforces! <img src="/predownloaded/be/de/bede115074d89e31af9bec68662549e90587cf99.png" style="width:250px;float:right;margin:0 1em 1em 1em;"/> We are [Ethflow](https://ethflow.io) &mdash; proprietary trading fund, specializing in cryptocurrency trading. We are glad to host our first Codeforces round! All participants will **have a chance to win T-shirts** (top 50 + 50 random participants who ranked below 50th place and solved at least 3 problems). <center><img alt="image" src="/predownloaded/ef/67/ef67cdf961558f2fbc67b241dc95c5a11a12eed5.png" style="float:center;height: 400px; margin: 10px; max-width:80%;"/></center> Many of our team members, such as [user:VEGAnn,2025-01-24], [user:_Time_Lord_,2025-01-24], [user:welleyth,2025-01-24], [user:FLEA,2025-01-24], [user:vgzowski,2025-01-24] and others, are former Codeforces participants, including our CEO, [user:altruist, 2025-01-24] and CTO, [user:SoMuchDrama,2025-01-24]. Now, some of them were involved in four different ...

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CF Analytics — not just stats, but actual coaching Hey Codeforces! Built something I think you'll find useful. **CF Analytics** — not just stats, but actual coaching. It pulls your full submission and contest history and gives you a real picture of where you stand and what to do next. ## What's inside: * Rating history, contest progression, activity heatmap * Topic-strength radar across 30+ algorithm tags * Weakness analysis based on your actual submission patterns * AI-generated personalized roadmap toward your target rating * Curated problem recommendations for your weak spots The AI part actually looks at your data — not generic *"practice DP and graphs"* advice. It gives you a concrete plan based on what you've been solving and where you're dropping problems. ## Links [Live Link](https://cfanalytics-frontend.vercel.app/) [GitHub](https://github.com/greenheaven24/cfanalytics) Free and open source. Try it with your handle and let me know in the comments if the weakness analysis matches what you'd exp...

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Codeforces: summarizing 2011 <p> Hi everybody! </p> <p> The calendar shows the end of December — the year 2011 is about to end. It was an eventful and exciting time for us. You can find pictures below summarizing 2011 in comparison to 2010. In a nutshell, we've made it! We have grown in all parameters! This result is the shared victory of the well-united team. My special thanks go to the VK (VKontakte) and specifically — to Pavel Durov. The programmers' community and its development really matters to them. I want to thank the authors of the problems: preparing contests is tough and you are a significant help to the Codeforces project and to the whole community. </p> <p> So, comparing the ending 2011 year and the 2010 year in pictures goes like this: </p> <center style="margin-bottom: 3.0em;"><img src="http://assets.codeforces.com/images/statistics-2011/total-registered-users-2010-2011-en.png" style="margin: 0.5em;display: block;" /> <small>Codeforces users' growth throughout the Codefor...

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Квалификационный раунд Yandex Cup 2023 Всем привет! Недавно мы публиковали [новость](https://codeforces.me/blog/entry/121128) про старт регистрации на квалификационный раунд в рамках отбора на [Yandex Cup 2023](https://yandex.ru/cup/?utm_source=partnet&utm_medium=site&utm_campaign=cup23&utm_content=codeforces). Чемпионат состоит из шести направлений: - [Алгоритм](https://yandex.ru/cup/algorithm/?utm_source=partner&utm_medium=site&utm_campaign=cup23&utm_content=codeforces) ❤️ - [Бэкенд разработка](https://yandex.ru/cup/backend/?utm_source=partner&utm_medium=site&utm_campaign=cup23&utm_content=codeforces) - [Фронтенд разработка](https://yandex.ru/cup/frontend/?utm_source=partner&utm_medium=site&utm_campaign=cup23&utm_content=codeforces) - [Машинное обучение](https://yandex.ru/cup/ml/?utm_source=partner&utm_medium=site&utm_campaign=cup23&utm_content=codeforces) - [Аналитика данных](https://yandex.ru/cup/analytics/?utm_source=partner&utm_medium=site&utm_campaign=cup23&utm_content=codeforces) - [Мобильная разработ...

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CSES Pro: Collapsible Progress Dashboard, Codeforces-style Copy/Paste & Star Bookmarks Hello Codeforces Community! The CSES Problemset (cses.fi) is widely considered one of the best platforms for mastering core algorithms and data structures. However, compared to platforms like Codeforces, it lacks a few quality-of-life features that can make your practice workflow much smoother. Specifically: 1. You have to save your code to a file locally just to upload and submit it. 2. There are no copy buttons on the input/output sample test cases. 3. There is no built-in way to bookmark/star tasks you want to review later. 4. There is no dynamic category-wise progress tracker, solve streak counter, or random problem selector. To solve these annoyances, I built CSES Pro -- a lightweight, completely free, and open-source Chrome Extension that injects these features directly into the native CSES site. --- ## Feature Showcase ### 1. Codeforces-Style Submit Editor No more saving temporary .cpp or .py files on your desktop just to upload them. The extension repl...

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Some statistics: who are we? <img src="http://assets.codeforces.com/files/codeforces-apr-may-2010/codeforces-apr-may-2010-countries.jpg" style="margin:1em;float:left;"> <p> This post contains few words and many pictures. I decided to publish statistics on Codeforces visitors for the past two months. Why? I believe that it might be interesting. I took pictures from <a href="http://www.google.com/analytics/">Google Analitycs</a>. </p> <p> Codeforces was born little more than 4 months ago. During this time, we held <a href="http://codeforces.me/contests">16 contests</a> (though one of them was non-rated). There are more than 4000 registered users, and every day we get about 30 more. There are 1797 coders participated in the contests, many of them participate in our contests regularly. The average number of registrations for one competition is growing, and I want to believe that soon it will conquer psychological barrier 1000 users. Also codeforces social network is popular: more than 400 posts, almost ...

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I combined 6 different Codeforces extensions into one lightweight workspace (CF Monolith)  Hey guys, Like many of you, my browser extensions setup during a live round was a total mess. I had one extension just for dark mode, another for rating predictions, another to hide tags, and a few more for random stats. Running all of them together was actively lagging my UI, especially during the final minutes of a contest. To fix this, I spent the last few weeks building a single, unified workspace from scratch called **CF Monolith**. It’s built entirely on vanilla JS and Manifest V3, so it has near-zero overhead and won't lag your browser when the contest clock hits zero. It runs 100% client-side with no tracking or external database dependencies. I wanted to make something that actually improves the workflow for both live rounds and upsolving. Here is what it does: - **Instant GM Code Viewing**: When you're upsolving, you can view the exact code of top leaderboard finishers with a single click r...

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Stop making extensions!!!!! In the words of the late John F. Kennedy: "We choose to do things not because they are useful, but because they are excuses to vibecode another Codeforces extension". People were confused when he said this because they didn't know what "Codeforces" meant. The Soviets interpreted it as a subtle threat about American capabilities in the yet uncharted field of cyberwarfare. But I digress. There's no need to make 998244353 extensions to do things that you can do with existing options (or better yet, vanilla site functionality). - If you want dark mode, use dark reader. You also get dark mode on other websites. - If you want simple analytics about your profile, use CF Analytics. - If you want estimated rating changes, use carrot. - For anything else, it's probably already possible in the vanilla site.

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Эти расширения могут быть вам полезны **Привет Codeforces!** Многие пользователи [codeforces.com](http://codeforces.com) могут знать об этих расширениях. Но есть пользователи, которые могут не знать. Вот почему я хочу поделиться этими расширениями. Первый очередь в нашем списке это &mdash; **Carrot** [Магазин расширений Chrome](https://chrome.google.com/webstore/detail/carrot/gakohpplicjdhhfllilcjpfildodfnnn/related) — это ссылка на расширение в **Google Chrome**. **p.s**. Поскольку я использую Google Chrome, все ссылки только на Google Chrome **Carrot** — это расширение позволяет вам видеть, сколько рейтингов оно вам дает во время соревнования. Однако расширение может быть не таким точным, как предполагалось. Во время соревнования: Carrot вычисляет изменения рейтинга в соответствии с текущим положением, когда вы открываете рейтинг, и отображает их в новом столбце. Carrot также добавляет столбец, показывающий дельту, необходимую для повышения ранга. Расчет дельты выполняется в режиме реального времени...

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Unveiling Codeforces Insights: Explore Your Coding Journey with Advanced Analytics Hey Codeforces community! I'm excited to share with you a project I've been working on that brings a new dimension to our coding journeys – **Codeforces Insights**! Its a humble attempt to tweak a few things on the pre-existing Codeforces Visualizer ### What is Codeforces Insights? Codeforces Insights is a web application designed to offer a deeper understanding of your Codeforces performance through interactive visualizations and advanced analytics. Whether you're a seasoned coder or just getting started, this tool aims to enhance your coding experience. ### Key Features: 1. **Rating Predictions:** Visualize the trajectory of your Codeforces ratings using state-of-the-art forecasting models. 2. **Submission Analysis:** Explore the distribution of verdicts for your submissions and discover your preferred programming languages. 3. **Problem Analysis:** Gain insights into the distribution of problems solved based on difficulty levels and problem tags. 4. **User S...

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[Update] CF Custom Contests: Level Up with New Analytics & Firefox Support! Hey everyone! Last week, I launched **Codeforces Custom Contests**, a [Chrome extension](https://chromewebstore.google.com/detail/iafalaippdkpmfpicnhoccfbbkgnelpg?utm_source=cf-blog) (now on [Firefox](https://addons.mozilla.org/en-US/firefox/addon/codeforces-custom-contests/) too) to instantly create personalized contests. I just wanted to thank you all for your support as there are over 300 new users in just one week! **Summary for New Users:** Create custom contests instantly and analyze your results to efficiently train and improve your rating! See more info in the [previous post](https://codeforces.me/blog/entry/142733) I’ve incorporated feedback and suggestions on the previous post and shipped a major update. Here’s the details! What's New ------------------ - **Advanced Post-Contest Analytics:** Track your progress and find your weaknesses with detailed performance metrics. See accuracy by tag/rating, a contest history, an upsolve list, and more! - **Problem Tags Fil...

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[Tool] CommitForce: auto-sync your Accepted solutions to GitHub (no open tab, contest-safe) Hey Codeforces, Like many of you, I wanted an automated, hands-off way to back up all my Accepted solutions to GitHub so I could review my progress over time. However, after trying existing extensions out there, I kept running into recurring issues: * **Requiring an active Codeforces tab session:** Many tools rely on content scripts scraping the DOM. If you practice using CLion/VS Code, close your tabs, or submit through tools like Competitive Companion, sync fails. * **Hidden tabs popping up:** Some tools spawn pinned/hidden tabs (`chrome.tabs.create`), which break with `ACCESS_DENIED_ERROR` on contest submissions. * **Overwriting solutions:** Most tools key by Problem ID (e.g. `1872A.cpp`). If you solve a problem with brute force and later rewrite an optimized $O(N \log N)$ version or port it to Rust, your earlier Accepted attempt gets overwritten. * **Plagiarism risk:** Pushing solutions immediately to a public repository during live rated contests creates a real r...

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Beyond the Contest: How Competitive Programming Powers Real Life and Sports If you've ever done competitive programming (CP), you know the drill — segment trees at 2 AM, dynamic programming (DP) transitions that make your head spin, graphs that refuse to be traversed efficiently. It's easy to dismiss this as "just contest stuff." But the truth is, almost every algorithm you grind on Codeforces or LeetCode has a real job somewhere in the world — and one of the most fun places to see this is sports. This post covers two things: Everyday, real-life uses of classic CP concepts. A deep dive into how algorithms — especially DP — quietly run the show in cricket, tennis, basketball, football, chess, and more. **Part 1: CP Concepts You Already Know, Working in the Real World** **** **Sorting & Searching** **** Every time you sort products by price on Amazon or search for a contact on your phone, you're using variants of merge sort, quicksort, or binary search. Databases use B-trees (a generalization of binary search trees) to fetch records in logari...

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Introduction to Competitive Machine Learning I realized a lot of people keep pursuing and learning Competitive Programming because they get addicted to Rankings & Ratings. In this blog i have tried to help you exploit your same existing mechanism and learn Machine Learning in the process while pursuing it a competitive way. _I have drawn examples from around 10 kaggle Competitions_ and illustrated what works and what doesn't , what is important and what is not and how much time usually it takes for each step while competing. I have also heavily linked through the blog post and it contains more than enough links for you to start competing on Kaggle or Analytics Vidhya seriously. [Link to original Blog Post on "Introduction to Competitive Machine Learning"](https://threads-iiith.quora.com/Introduction-to-Competitive-Machine-Learning) Also last event by Threads, Felicity'18 called ["Kings of Machine Learning"](http://simplernow.com/redirects/koml.php) is still live. There is Rs 15,000 cash prizes and 20 T-shirts up for th...

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CF FetchCodes => See Friends' Accepted Codes + AI Explainer + Dark Mode on CodeForces ### CF FetchCodes Source: **Chrome Web Store:** [Install CF FetchCodes](https://chromewebstore.google.com/detail/cf-fetchcodes/ombmefkchmjbodcoboeagbpaejfojnga) **GitHub (Open Source):** [github.com/sayanpaulcse/CF_FetchCodes](https://github.com/sayanpaulcse/CF_FetchCodes) --- ### What is CF FetchCodes? It's a browser extension that adds a small widget to every Codeforces problem page. It lets you: 1. **See which of your friends solved the problem** — detected automatically from your CF friends list. 2. **Read their accepted code** — with syntax highlighting, right on the page. No navigation needed. 3. **Ask AI to explain any solution** — a built-in Gemini chat that breaks down the approach, time/space complexity, and logic. 4. **Dark Mode for Codeforces** — full page dark mode + code-only dark mode with 6 selectable syntax themes. --- ### Feature Breakdown **1. Accepted Codes of Friends** After a contest ends, go to any problem page and click "Show Code...

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CF Analytics Pro — Compare up to 10 Codeforces Users Across Every Metric Hi everyone! I recently built CF Analytics Pro, a free analytics dashboard for Codeforces that lets you compare up to 10 users simultaneously across ratings, contests, difficulty, tags, milestones, heatmaps and many other statistics. The project uses the official Codeforces API and computes all analytics automatically. **Live Demo** ------------------ https://cfanalyze-skrl.vercel.app **GitHub** ------------------ https://github.com/Shivansh4171/cfanalyze       I wanted a dashboard where multiple Codeforces users could ...

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I built a tool to help track ICPC prep and Codeforces progress Hey Codeforces! Preparing for ICPC can be pretty overwhelming. Whether you're just trying to pass your regionals or aiming for the World Finals, it's hard to keep track of what you actually need to study, what your weak topics are, and how much progress you're making over time. I wanted something to make the grind a little more structured, so I built a side project called ICPC Prep Hub. I’ve been working on it for a while and wanted to share it with you all today. It’s completely free and open-source. To make it super easy to use, there are no passwords to remember—you just verify your CF handle once, and it saves your progress across all your devices. What does it actually do? CF Analytics & Recommendations: The site syncs your solved problems straight from Codeforces. You can see your rating graph, check your accuracy, topic wise rating, and compare the problem tags you solve (like DP vs. Math) against other real users or the top N users. This makes it really easy to see...

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# CF Tracker – Track Your Codeforces Progress Like Never Before **Hello Codeforces! ** I’m excited to share a personal project I’ve been working on: CF Tracker — a full-featured analytics tool to help you and your friends monitor progress on Codeforces with clean visualizations and real-time stats. Live link : [https://cfanalyzerbit.onrender.com/](https://cfanalyzerbit.onrender.com/) ** What is CF Tracker?** CF Tracker is a full-stack web app that uses the Codeforces API to provide deep insights into your performance, consistency, and strengths as a competitive programmer. Whether you want to stay consistent, analyze your weaknesses, or compare with friends, this tool is built for you. ** Key Features** ** Today's Stats** ****Problems solved today - Number of submissions - - Verdicts: AC, WA, TLE, etc. - - Problem rating distribution for today ** All-Time Statistics** - Problem Solving Progress (line chart – 30 days, 6 months, all time) - - Contest Rating Graph (rating, rank, rating changes) - - Submission Activit...

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Introducing AlgoRadar: An Open-Source Chrome Extension for Competitive Programming Contests Hello everyone, I often missed upcoming contests across Codeforces, AtCoder, LeetCode, and CodeChef, so I built **AlgoRadar** an open-source Chrome extension that brings upcoming competitive programming contests from multiple platforms into one place. <img src="/predownloaded/68/a0/68a0f1acaeb0a3c012d19042e12454929ae57191.png" /> <h3 style="margin-bottom: 12px;">✨ Features at a glance:</h3> <ul> <li><b>Multiple Platforms:</b> One unified interface for Codeforces, LeetCode, AtCoder, CodeChef, and more soon.</li> <li><b>Smart Filtering:</b> Filter contests by platform and time range ("Today", "This Week", or "This Month") so you only see events that matter to you.</li> <li><b>Live Countdown Timers: </b>See exactly how much time remains before registration or contest start, automatically adapted to your computer's local timezone.</i>.</li> <li><b>Fast Performance: </b>Only 88 KiB in size, with background synchronization and caching to keep contest data fresh.</li> ...

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Some Useful chrome extension for codeforces 1. [Carrot](https://chromewebstore.google.com/detail/carrot/gakohpplicjdhhfllilcjpfildodfnnn) predicts rating change and analys performance. 2. [CF Analytics](https://chromewebstore.google.com/detail/cf-analytics/hhljbjodjdbjbggddjaidojnlmaobcpo) Analyse profiles. Include statistics of problems solved. A bar chart showing problems solved for each problem rating, a doughnut chart displaying tags solved across any problem and also lists a count for each tag. The ‘Unsolved Problems’ shows a count of all problems attempted with not correct verdict and also lists them. 3. [CF Tracker](https://chromewebstore.google.com/detail/cf-tracker/hadiffebpglmdnknojeoelfgmjleiecc) keeps track of spent time on a particular problem. 4. [Codeforces Practice Tracker](https://chromewebstore.google.com/detail/codeforces-practice-track/cnahgdhboflcnojgmeehhhfeoojifonm) you can Read overview section of this extension. **Bonus:** [Dark Reader](https://chromewebstore.google.com/detail/dark-r...

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Yandex Cup 2025: follow live broadcast! Hello Codeforces! The Yandex Cup finals already started! We're streaming live from the Istanbul. <center> <iframe width="560" height="315" src="https://www.youtube.com/embed/6R7iwYAXKLY" style="margin: 1em; title="YouTube video player" frameborder="0" allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share" referrerpolicy="strict-origin-when-cross-origin" allowfullscreen></iframe> </center> Also follow the leaderboards: _Main stream_ - [Analytics](https://new.contest.yandex.com/contests/86159/leaderboard) - [Algorithm](https://new.contest.yandex.com/contests/86430/leaderboard) - [Backend] (https://new.contest.yandex.com/contests/84808/leaderboard) - [Machine Learning] (https://new.contest.yandex.com/contests/86506/leaderboard) - [Frontend] (https://new.contest.yandex.com/contests/86107/leaderboard) - [Mobile Development] (https://new.contest.yandex.com/contests/86170/leaderboard) _Juniors_ - [Machine Learnin...

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TypeDB Forces 2023 Greetings, Codeforces! <center> <img alt="TypeDB" src="https://codeforces.me/predownloaded/5b/53/5b53391f00afc2baed514108cdfef71071f66bce.png" style="height: 150px; margin: 15px; max-width:50%;"/> </center> We are excited to announce **TypeDB Forces**, which will take place on [Sunday 29th of January](https://www.timeanddate.com/worldclock/fixedtime.html?day=29&month=1&year=2023&hour=17&min=35&sec=0&p1=166) – our first competition of 2023, with hopefully many more to come! We’re from [Vaticle](https://vaticle.com), and we’re the creators of [TypeDB](https://github.com/vaticle/typedb) & [TypeQL](https://github.com/vaticle/typeql). TypeDB is a strongly-typed database, and we are building a team of world-class engineers to work on next generation database architectures, language compilers, type systems, reasoning engines, IDEs, and cloud infrastructures. Top scorers will earn cash rewards and swag, but we’re most excited to invite all the top performers of this round, from anyw...

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How to unsubmit a previously submitted solution? Hello everyone! I wanted to know if there exists any way by which we can undo the Accepted submission for a solution which was submitted by me previously at some point of time, or at least make it such that the problem goes to the unsolved section and not in the solved section. **Reason:** I am using the CF Analytics Extension which basically shows the number of problems solved for each rating range in the form of a bar graph. I noticed that my 800 rated problems solved are too high and it overshadows my other higher rated problems in the graph. This is because I earlier used to solve 800 rated problems to maintain my daily streak and now I regret it heavily when I look at my chart. For instance, consider the given two graphs: 1. [user:vjudge.7,2024-09-08]  2. [user:Benq,2024-09-08] $\displaystyle orz$  As you can clear...

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AetherCP — A Local-First Analytics Extension for Codeforces AetherCP — A Local-First Competitive Programming Companion Hello everyone! Over the past few months I've been working on a side project called AetherCP, a Chrome extension built specifically for competitive programmers. The idea started from a simple problem. Most existing tools can tell you how many problems you've solved, but they don't really help you understand your practice habits. So I decided to build something focused on practice analytics rather than only submission counts. Features Automatic timer while solving problems 5-minute idle detection Daily productivity analytics Full-year activity heatmap Topic-wise solved problem analysis Rating distribution charts Recent practice history VS Code Competitive Companion integration Local-first storage (no mandatory account) Everything runs locally inside the browser, so your practice data stays on your own machine. Why I built it I wanted something that could answer questions like: Which topics ...

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AlgoAtlas: A New Platform for Competitive Programming Training Hello Codeforces community! I'm excited to introduce AlgoAtlas, a platform I've been developing with a standout feature that many CP enthusiasts have been asking for: a truly advanced competitive programming compiler. Key Features Advanced Code Compiler - Multi-language support (C++, Python, Java) - Real-time execution metrics showing time and space complexity analysis - Detailed performance metrics for your submissions - Streamlined test case management system Personalized Virtual Gym - Custom contests targeting specific algorithm classes you want to improve - Adaptive difficulty progression that evolves with your skill level - Spaced repetition system to reinforce concepts at optimal intervals - Detailed level sheets to track your progression across different topics Contest Analytics - Calendar integration with major competitive programming platforms Structured Learning Paths - Expert-designed curriculum with clear progression markers. It is somewhat like ...

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AlgoAtlas Milestone: 230+ Stable Users, 1200+ Visitors and 10,000+ Views — Thank You, Codeforces! Hello Codeforces community! I'm genuinely blown away by the response to [AlgoAtlas](http://algoatlas.tech) and wanted to share some exciting metrics with everyone who has supported this journey. In just a short time since our initial announcement, we've reached: - 230+ Stable Users - 1,200+ unique visitors - 10,000+ page views - Users from 37+ countries worldwide These numbers far exceed anything I imagined when first sharing [AlgoAtlas](http://algoatlas.tech) with the community, and I'm incredibly grateful for your interest, feedback, and participation. What's been most popular so far: - Our multi-language compiler with real-time performance metrics - The structured learning paths for systematic algorithm mastery - AI-powered hints and code analysis - The personalized virtual gym with adaptive difficulty Based on your feedback, we've continuously improved the platform: - Optimized the compiler for faster execution - Enhanced the UI/UX for a smoother learning e...

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I Turned My Statistics Class Into Something Useless This semester I'm taking statistics and probability at university, and one question came to my mind: why not apply some of this to something I actually use? And here we are The result is **LeekCF-Analytics**. Open any Codeforces profile and a new panel appears. It shows every change in your rating, contest by contest:  It skips your first three contests. I don't think it serves any real purpose, but if you're curious, you can get it from [GitHub](https://github.com/ahmadsh2007/LeekCF-Analytics), the [Chrome Web Store](https://chromewebstore.google.com/detail/leekcf-analytics/icaonbanohblkhbomajmcibkampjjlkp), or [Firefox](https://addons.mozilla.org/en-US/firefox/addon/leekcf-analytics/) Add-ons. ### Go check your negative delta in a beautiful way

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Codeforces Aggregator Hello Codeforces Community! Have you ever tried to find a common unsolved problem for you and your friends to practice on? Or maybe you wanted to quickly compare your combined problem-solving stats without juggling multiple browser tabs? It can be a hassle, right? Therefore, hereby I present to you [CF aggregrator](https://cf-aggregator.vercel.app/) !! CF Aggregator is a simple, fast, and clean web tool that lets you combine data from multiple Codeforces handles into a single, unified dashboard. What Can It Do? Multi-Handle Aggregation: Just enter a few handles separated by commas, and the tool will fetch and combine all the data for you. It's perfect for teams or practice groups. Combined Dashboard: Get a quick overview of your group's collective stats. See the total unique problems solved, the highest max rating in the group, total submissions, and more. Visual Statistics Tab: A very smart idea to track progress inspired by **cf analytics** Smart Problem Fin...

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Atcoder extension for mozilla Hello all!! I have recently extended the AtCoder Chrome extension for Mozilla as well. The _CF blog_ regarding the chrome extension is described [here](https://codeforces.me/blog/entry/130898). **Link to Mozilla AtCoder extension**: [AC Analytics](https://addons.mozilla.org/en-US/firefox/addon/ac-analytics/) Please let me know if there are any bugs to be fixed, although there shouldn't be any since it has already been on chrome for a year now. Thanks!!

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Machine Learning in Everyday Life In today's fast-paced digital world, Machine Learning (ML) has quietly become a powerful engine behind many of the tools and technologies we use daily. From personalized recommendations on streaming platforms to advanced medical diagnostics, ML is revolutionizing industries and enhancing our day-to-day experiences. But what exactly are its applications in the real world today? Let’s dive into some of the most impactful uses of machine learning in 2025. 1. Personalized Recommendations Whenever you see a curated playlist on Spotify, a suggested video on YouTube, or product recommendations on Amazon, machine learning is hard at work behind the scenes. These platforms use ML algorithms to analyze user behavior, preferences, and history to tailor content uniquely for each user. 2. Healthcare and Diagnostics ML is transforming healthcare by helping doctors diagnose diseases faster and more accurately. Algorithms can analyze X-rays, MRIs, and even genetic data to detect anomalies ...

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Make a Flying Drone together with CROC Being recently in the CROC office, I've heard about another interesting contest. It's called "Flying Robots". I am far from robots, but the subject is interesting and popular. I am pleased to publish a small announcement. ### About contest September 3, 2012. CROC, one of the five largest IT companies in Russia, calls for Flying Drone contest applications. The contest is a part of the '20 Ways to Brighten Up Your Life' project. The first prize will be **1 million** Rubles. Contestants shall make a pilotless and autonomous drone which must take off from a starting point, overcome an obstacle, land within a certain zone, take off again and then come back to the starting point. Please submit your application till November 15, 2012. For contest details please visit [http://robots.croc.ru/](http://robots.croc.ru/) (in Russian). Results announcement and award ceremony will take place in August 2013. ### About CROC CROC is a leader in IT infrastructure design and implement...

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How to progress? Finally hit expert, now my next target is candidate master. I'd love to hear advice from people more skilled and experienced than me. If you have CF Analytics, can you check out my profile and see what I need to start doing to solve Div 2 D consistently? I'm considering working through some key sections in CSES (Sorting and Searching to improve my binary search on answer intuition, Tree Algorithms, Graph Algorithms, DP because I suck at complex DP, and Range Queries to finally learn segment trees). Maybe I just need to solve more problems as I've only done 230 so far. I recently graduated from college with a degree in mathematics, but I feel like I'm not exploiting my math knowledge enough. For example, my combinatorial reasoning is good but I rarely come across problems in the Div 2 A-D range that require it. Should I start looking at later problems from competitions for those kinds of problems? I always hear that my math intuition should help me a lot in competitive programming...

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AtCoder Analytics — a Chrome extension for AtCoder profiles Hi everyone, I just published AtCoder Analytics, a Chrome extension that adds extra stats to AtCoder user profile pages. I started this because I noticed another AtCoder-related extension I used stopped working (likely due to site/API changes), so I decided to build a lightweight alternative and publish it. Features - Solved-by-difficulty histogram (estimated difficulty) - Solved breakdown by contest series (ABC/ARC/AGC/AHC/etc.) - Unsolved list (with links) Chrome Web Store link: https://chromewebstore.google.com/detail/bmfjngielhkffoekjpdgpedpmelhabhm?utm_source=item-share-cb Feedback and bug reports are welcome.

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Blitz1v1 — A Real-Time 1v1 Coding Battle Platform **The Codeforces BlitzCup format felt very exciting and competitive.** Inspired by that, we explored whether similar real-time 1v1 coding platforms exist. While some options were available, none delivered the experience we were looking for, so we decided to build our own!! **Introducing [Blitz1v1](https://blitz1v1.onrender.com/)** Blitz1v1 is a real-time competitive coding platform designed for 1v1 Codeforces-style duels where two players solve the same problem simultaneously and compete for the fastest correct submission Key Features: - Real-time 1v1 coding duels. - **Arenas and tournament brackets**. - Live pairing: instantly match with available opponents for immediate duels - A global **Open Challenge** where anyone can join, chat in real time, adjust configs, and accept - Direct Challenge to anyone via **Open Challenge** - Integration with Codeforces API for automatic submission validation. - Fair play mechanisms such as problem locking and timed rounds. -...

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Introduction to CP Tracker -- A Web-Based Competitive Programming Archive & Management Tool Introduction ==================  CP Tracker (Competitive Programming Tracker) is a comprehensive tool I maintain for archiving and managing your competitive programming progress. [Live Demo](https://competitive-programming-tracker.netlify.app/) | [GitHub Repository](https://github.com/lihaoze123/cptracker) Core Highlights ------------------ * One-Click Import: Seamlessly import submission records from major platforms including Codeforces, AtCoder, Luogu, and QOJ. * Visual Analytics: Built-in interactive charts and dynamic heatmaps intuitively visualize your daily activity and skill growth curves. * Rich Text Support: Native rendering support for Markdown and LaTeX mathematical formulas. * Data Flexibility: Full support for CSV import and export. * Storage & Sharing: Supports local offline storage. You can also choose cloud synchronization to generate a personal public profile and share your pro...

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Announcing turboCP, a tool to help upskill faster in competitive programming Hi, I'm officially announcing **turboCP** &mdash; my personal effort to help competitive problem solvers practice and upskill with greater clarity and consistency. turboCP is a platform which provides you, as a problem solver, everything you need to up your game, all at one place. 1. **Daily Challenges**: You will get a daily problem from codeforces which is uniquely selected for your skill level. The problems level up as you do. 2. **Streaks**: We all know how addictive streaks are. Solve the daily problem to maintain streaks and stay consistent. 3. **Detailed Analytics**: See which topics you haven't practiced or struggle with, average time you take to solve questions of different difficulties, accuracy, detailed roadmaps and much more. 4. **Custom Contests**: Create and practice with your own timed custom contests, with detailed contest analysis. **Join the waitlist here** &mdash; [https://turbocp.vercel.app/](https://turbocp.vercel.app/) (check Promotions label ...

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Learning Roadmap for a Data Analyst **The very first question to hit our mind is who is a data analyst? What do they do?.** In simple words, a data analyst is responsible for collecting data, processing it, and analyzing it to find sensible insights for decision making. In most cases, an analyst will work on the raw data, grind it to produce action-oriented insights. Most of the analysts won’t work on the core machine learning or the deep learning models. A data analyst will make use of multiple tools to process the data and work with it. Having experience in working with different tools and statistics is most important for them. In the next blocks, we will be discussing each skill and related certifications as well. **1. Statistics** For every data professional, stats and math are the must-haves. Because, without the knowledge of stats and probability, one cannot able to interpret the data effectively. Some of the major topics include descriptive and inferential stats. If you are a pure beginner, you ...

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CF Themer: dark themes, focus mode, timer and mashup contests (Chrome extension) Hey fellow coders, I made a Chrome extension called CF Themer. Install: https://chromewebstore.google.com/detail/fogjbemaajokjgplblhlibebfjpbdjfd Why I made it: I spend a lot of time on Codeforces, and three things kept bothering me: 1) The white site is hard on the eyes during late-night practice. 2) I wanted a timer and a place for notes on each problem without leaving the page. 3) Building a good practice set by hand takes ages, and the problemset filters don't give you a contest. What's in it: - Themes: Monokai, Dracula, Pure Black and Lock-In. Switch with the popup, the ◐ button, or Alt+Shift+T. - Focus mode (Alt+Shift+F): shows only the problem statement. - Timer and notes: one per problem, saved in your browser. - Spoiler-free mode: hide tags, difficulty and solved counts. - Mashup contests: pick tags, rating range, number of problems and length. It builds a contest, runs a countdown across Codeforces, hides tags and ratings until it ends, then scores you ...

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Submission in groups are hidden in Problem Set and Contests **Hey guys,** Hope you are fine When I solved a problem in a group or a contest that a friend collect or something like that. The problem appeared like accepted in the problem set and the contest but I can't see my submission. And in most cases I don't remember the group or the contest I solved the problem in. **like that,** I can't see the submissions but I knew I solved them. I know I can solve them again, but I love do some analytics and see my old code.  So I want to know is there are anyway to find the submission? **Thanks for consideration** all Love **Update:** I think It's good idea to add a search by problem code in "My Submissions" Filter so you can see all submissions you make for a specific problem in different places. **Here** 

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KYCS — (Know Your CodeForces Submission) I have created certain CodeForces submission visualization some days back (can be found in my previous blog entries). And getting a really positive response, I thought of combining all of them at one place and make them easy to use which obviously needs deploying to web and needs nothing more than a good internet. So, I have come up with this small Dash python app which allows us to create really nice data analytics app and the main thing is its OpenSource. Just follow the instructions written in the top left corner of the [page](https://kycs.herokuapp.com/) when it's launched from the web. They will look something like this:  It's as easy to follow as it sounds. (Link to the [app](https://kycs.herokuapp.com/)) <br> Also if someone would like to contribute, then source code is [here](https://github.com/JeetKaria06/KYCS). ![Output2](/predownloaded/1a/0c/1a0c481d01e6149295618160670720825c4c7b81....

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Should I Focus on Projects or Aim for a CCO Medal? Lately, I’ve been asking myself a big question: what’s the best path to stand out for admission into top universities in Canada and the U.S.? Should I invest my time into creating a few meaningful projects, or should I give my absolute best to earn a medal at the Canadian Computing Olympiad (CCO)? Option 1: Build 3 Projects Here are the three projects I’m considering: 1. Competitive Programming Tracker – A web app that tracks coding contest progress, offering analytics and recommendations for improvement. 2. QuantSim – A simulation tool for basic trading strategies, designed for students curious about quantitative finance. 3. Euclid Puzzle Generator – A platform that generates math competition–style problems with step-by-step solutions. Option 2: Aim for a CCO Medal On the other hand, winning a medal at the CCO is one of the strongest signals of programming ability in Canada. It’s highly respected by top universities like Waterloo, MIT, and U of T. A medal could demon...

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Codeforces MCP Tools — 11 AI-powered analytics tools for CP, now live! Hello Codeforces! I've been working on making Codeforces data more accessible to AI agents — and I'm excited to share something you can start using right away. Introducing **Codeforces MCP Tools** — a Model Context Protocol server that turns the Codeforces API into **11 strictly-typed AI tools**. Plug it into Claude Desktop, Cursor, VS Code, or any MCP-compatible client, and your AI assistant instantly becomes Codeforces-aware. **What it can do:** - **get_user_stats** — full profile, rating, rank, solve counts - **get_rating_history** — every rating change + latest contest performance - **get_tag_breakdown** — how many problems you've solved per tag - **analyze_weak_topics** — finds your weakest tags from lowest-rated solves - **get_recommend_problems** — smart suggestions based on your rating + weak tags - **get_search_problems** — filter problemset by tags / rating range - **get_virtual_contest** — custom practice contests excluding solved problems - ...

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Impact of AI in current job market Artificial Intelligence (AI) is no longer a futuristic concept—it is a present-day force actively reshaping the global job market. From automating repetitive tasks to augmenting human decision-making, AI is influencing how we work, what skills are valuable, and how industries evolve. The impact is neither entirely positive nor negative; instead, it is a complex transformation that demands adaptation. **Automation: Efficiency vs Displacement** One of the most visible effects of AI is automation. Tasks that once required human effort—data entry, customer support, basic analysis—can now be handled by intelligent systems. This has led to increased efficiency and reduced operational costs for companies. However, automation also raises concerns about job displacement. Roles that are routine and predictable are more vulnerable. For example, clerical work, manufacturing line jobs, and even some entry-level programming tasks are being partially or fully automated. This creates uncertain...

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Competitive Programing even works in Development too I'm working with the Retail Store Business Analytics team at AICOE JPL'23 this summer. My work revolves around improving **Computational time by Learning both Weights and Connections for Efficient Neural Networks further that can be utilized in LSTM Architecture**. Today, we encountered a problem while trying to reduce the computational complexity of multiplying two matrices with a majority of zero elements. I brainstormed for 1-2 hours and came up with the idea of **Sparse Matrix Multiplication** solely based on intuition, despite not having prior knowledge of it. **This is how CP works improving problem-solving skills, allowing you to refine your logic and enhance your Development skill as well.**

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Leetify - 3000+ users now - Friction-less solving. Hello everyone. Before anything else, this project comes from a place of appreciation for Codeforces. Leetify isn’t trying to redesign Codeforces. It’s trying to remove the friction around solving. My workflow used to look like: Problem → Code Editor → Notes → Submissions → Performance Analysis Constant tab switching. Constant context switching. Leetify brings those workflows into a single workspace with an integrated editor, notes, submissions, analytics, and other productivity features. Less switching. Faster solving. check it out : https://leetify-dun.vercel.app/

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How to increase the Rating on Codeforces ? I have studied and observed the patterns from the accounts which are already on the top levels. One thing is common among all. They all have solved an adequate amount of problems in their rating domains. One can set an arbitrary boundary of about 50 questions at each difficulty level. However, this may vary from person to person. Browser extensions like "CF Analytics" will be useful to get greater insights. During solving the problems fix time bound to better push limits. Don't wait for things to be finished then you will come and solve more problems. Learning things while solving will give your coding journey better efficiency. Good Luck and Happy Coding :)

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CodePulse: a simple tool to track your Codeforces growth and weaknesses Hi Codeforces, I made a small project called CodePulse — a Codeforces analytics dashboard built with Vite + React and deployed on **GitHub Pages**. It includes: * handle sync for contests and submissions * performance dashboard with key stats * charts for trends and rating changes * topic-wise strength/weakness analysis * problem history with search and filters * contest history * handle comparison * goals for rating, solved count, streaks, and contest participation * local-first storage with JSON import/export Link: https://advaybagaria.github.io/codepulse-cp-analytics/ I built it mainly to make practice tracking and review a bit more organized. Feedback and feature suggestions are welcome.

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Codeforces extensions you would want to have CF Analytics: https://chromewebstore.google.com/detail/cf-analytics/hhljbjodjdbjbggddjaidojnlmaobcpo CF World Standings: https://chromewebstore.google.com/detail/cf-world-standings/caginmipmmelcmijagfppgdljepiioak CF-predictor: https://chromewebstore.google.com/detail/cf-predictor/ocfloejijfhhkkdmheodbaanephbnfhn Codeforces Calender: https://chromewebstore.google.com/detail/codeforces-calendar/ehmnahdmmiibcbebjafdgjlomhnommpo Codeforces Practice Tracker: https://chromewebstore.google.com/detail/codeforces-practice-track/cnahgdhboflcnojgmeehhhfeoojifonm Codeforces Customizer: https://chromewebstore.google.com/detail/codeforces-customizer/akmlgflgekmnameijijkefhochekjfgg Codeforces Better Comments: https://chromewebstore.google.com/detail/codeforces-better-comment/dmkcpaljgkhdcachgfmplaoldejhafgn Carrot: https://chromewebstore.google.com/detail/carrot/gakohpplicjdhhfllilcjpfildodfnnn

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CF Analytics Extension not working CF analytics is not working properly, is it with all or just problem with my browser ? Please anyone suggest any other extension like this if their is.

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Chrome Extension Requestion — Analytics in Submission Tab I often want to find problems I did in my submissions tab (or stalking others) sorted by similar things like tags or rating as problemset tab. Is there anything for sorting problems by these features or at least displaying rating/tags besides submissions? If not I might make one, but would prefer to not have to do any work...

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SquadCode Update , GFG, AI Recommendations, Push Notifications & More Hello Codeforces! A few weeks ago I posted about [SquadCode](https://squadcode.me) , track LeetCode + Codeforces progress with your squad in one feed.Kept shipping since then. Here's what's new: https://squadcode.me What's new: • Codeforces Automation, auto-import any CF problem into our built-in playground, test your logic with one click, and auto- submit back to Codeforces directly from the app. • AI problem recommendations, suggests CF + LC problems matched to your current rating/level, add to a practice sheet in one click • Analytics page, personal solve charts, rating progression, streak history per member • Push notifications, get notified when a squadmate solves, when a challenge deadline is near, or for contest reminders (opt-in) • Auto challenge scoring, background worker now awards points automatically when you solve a challenge problem, no manual refresh needed • Shareable invite links, send a link directly instead of copying the raw code. Current sta...

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CF Analytics not working !!! Is anyone's cf analytics working? I can't see the bar graph, pie chart or unsolved question list anymore. Is this normal ?

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Help me solve this OA task Hello Codeforces! ================= Recently I gave this OA at Impact Analytics, but I couldn't understand this problem at all. The language of the problem statement isn't clear. Can someone just tell me whether the problem is correct? By that I mean can someone see if all the test inputs outputs make sense or not. [Here is the problem statement](https://drive.google.com/file/d/1w09f1hiJQYor3r8GRkrpd1bAtgTGdQg/view?usp=share_link) Thank you, bless you, Merry Christmas, Happy New Year!

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A Clean and Modern Codeforces Visualizer – cfstats.vercel.app Hey everyone! I noticed that most Codeforces visualizers out there are either outdated or not very user-friendly. So I built [cfstats.vercel.app](https://cfstats.vercel.app) — a clean, minimal, and fast Codeforces visualizer focused on analytics and simplicity. No login required. Just enter a handle and get instant stats. Would love your feedback!

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Codeforces extensions don't work Why codeforces extensions don't work? like, Carrot doesn't predicts delta change and CF analytics doesn't shows up extra info. tho they were working when recent div 3 started

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Best Online Tutorial for Learning Python Programming — 2019 Python is one of the most developer-friendly languages and also is the programming language of the year 2018 as ranked by the TIOBE Index. There are immense growth and development opportunities for professional skilled in Python. Numerous working domains like Data analytics, machine learning, web scraping, IoT, system automation, test automation are flooded with open positions for deserving candidates. Hence, one needs to learn the language from depth and breadth. Here are few of the simple and best online tutorials for learning Python. 1. [Python tutorial to learn step by step](https://www.techbeamers.com/python-tutorial-step-by-step/) 2. [Pythonspot](https://pythonspot.com/) 3. [Pythonguru](https://thepythonguru.com/) 4. [ProgramizPython](https://www.programiz.com/python-programming) Happy Python learning in 2019.

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