We invite ML students and specialists from all over the world to take part in the International Data Analysis Olympiad. HSE University and Yandex are organizing it for the 5th time, and the Otkritie bank will be our platinum partner this year.

Since it’s our first anniversary, we decided to change the format: students and ML specialists are divided into two separate divisions. Only students are able to join the main competition — the Student Division. All others can join the Open Division to participate hors concours (for their own interest).

Traditionally, the first stage’s task will be given by the Laboratory of Methods for Big Data Analysis (LAMBDA, HSE University). It will be about predicting the properties of two-dimensional crystals of various configurations. The task for the Finals will be provided by the Otkritie bank. The Olympiad includes two stages:

Online Stage (1-28 February 2022):

• Track 1: Traditional machine learning competition on Yandex.Contest platform. You will need to make new predictions and upload them to the automatic verification system.

• Track 2: Come up with a solution for the same problem, keeping within a rigid framework of time and memory used.

Final (16-17 April 2022, Moscow):

• top 30 teams according to the Online Stage results will be invited to the Online final.

• In the final 36 hours of the competition, participants will try not just to train the model, but to create a full-fledged prototype, which will be tested both in terms of accuracy and performance.

Registration is open till February 13: https://idao.world/

Hello, Codeforces!

On Dec/14/2021 17:35 (Moscow time) the Codeforces Round 760 (Div. 3) will start. This is a usual round for the participants from the third division. The round will contain 8 problems, which are mostly suited for participants with rating below 1600 (or we hope so). Although, as usual, participants with rating of 1600 and greater can register for the round unofficially.

The round will be hosted by rules of educational rounds (extended ACM-ICPC). Thus, during the round, solutions will be judged on preliminary tests, and after the round it will be a 12-hour phase of open hacks (we hope that our tests are strong enough, so there won't be too many solutions hacked during this phase).

You will have to solve 8 problems in 2 hours and 15 minutes. The penalty for a wrong submission is equal to 10 minutes.

We remind you that only the trusted participants of the third division will be included in the official standings table. As it is written on the blog which you can access by this link, this is a compulsory measure for combating unsporting behavior. To qualify as a trusted participant of the third division, you must:

• take part in at least two rated rounds (and solve at least one problem in each of them),
• not have a point of 1900 or higher in the rating.

Regardless of whether you are a trusted participant of the third division or not, if your rating is less than 1600, then the round will be rated for you.

The problems were prepared by Brovko, shnirelman, Lankin, awoo and me. We would like to thank the testers of the round: vovuh, Nil_Sinyaev, IsaacMoris, altynai, MarcosK, dese1sh, ZulaMostafa, nondeterministic, mumumucoder, peroon and kocko.

And, the last but not the least, thanks to Mike MikeMirzayanov Mirzayanov for Codeforces and Polygon systems!

Good luck in the contest! I hope you'll enjoy solving the problems we have prepared.

UPD: The editorial is out.

Hi all!

This weekend, at Dec/12/2021 18:15 (Moscow time) we will hold Codeforces Round 759 (Div. 2, based on Technocup 2022 Elimination Round 3). They are based on problems of Technocup 2022 Elimination Round 3 that will be held at the same time.

Technocup is a major olympiad for Russian-speaking high-school students, so if you fall into this category, please register at Technocup website and take part in the Elimination Round.

The Div.2 edition is open and rated. Register and enjoy the contests!

• The round authors are: Denisson, antonis.white, dimatimoshin23, napstablook, kirill.grachoff
• Thanks Makcum888, snowysecret, stevancv, wxhtzdy, and ijxjdjd for testing.

Have fun!

UPD: congratulations to the winners!

Technocup 2022 - Elimination Round 3

1. LeoPro
2. princebelkovetz
3. DDima
4. pelmenner
5. abdula-mon-fon-alibaba-A

Codeforces Round 759 (Div. 2, based on Technocup 2022 Elimination Round 3)

1. Maria_Akizuki
2. maxlevel_spyofgame
3. zhaojianmin
4. FlameDragon
5. Shawn

The editorial is published.

Hello, Codeforces community!

I'm glad to invite you to Codeforces Round #758 (Div.1 + Div. 2), which will be held on Dec/11/2021 13:05 (Moscow time). The round will be rated for both divisions. Note the unusual start time.

The problems were taken (mostly) from the ByteDance — Moscow Workshops Online Contest, which is happening at the same time. Tasks from the Online Contest are prepared by TadijaSebez and oversolver, additional tasks brought to you by Um_nik and gen. We are very thankful to the testers: Monogon, RedMachine-74, AmShZ, DeadlyCritic, errorgorn, oolimry and icypiggy for their time and great feedback. Also big thanks to authors of other problems of the Online Contest snarknews and I_love_kirill22 for cooperation, Bytedance instructors jqdai0815, Syloviaely, Gromah, Claris for testing and reviewing the Bytedance online contest, the contest coordinator antontrygubO_o for the great help in setting up that round and MikeMirzayanov for testlib.h, Polygon and Codeforces.

ByteDance is a global technology company operating a range of platforms that allow people across languages, cultures, and geographies to create, discover and connect. ByteDance has partnered with Moscow Workshops and Codeforces to organize a top-tier and exclusive training camp for the International Collegiate Programming Contest. The upcoming Programming Camp will be held in Beijing from February 17th to 23th, 2022.

ByteDance — Moscow Workshops Online Contest is an opportunity to participate as teams onsite in this camp. Due to COVID-19 restrictions, mainly teams from China can participate onsite this year. For the international teams, the opportunity of online participation is considered.

You can find more information about this training camp at https://programcamp.bytedance.com/.

UPD: The scoring distribution is 250 — 750 — 1000 — 1500 — 2000 — 2500 — 2750.

UPD 2: Editorial

Hi, Codeforces users!

We are announcing ITMO Winter Camp in Competitive Programming that will be held online. On each of the 10 days from January 10 to 21 (the weekend are the rest days) two-hour lecture and two-hour practice session is going to take place.

Each day one topic is covered, and the practice session is a set of problems of that topic. For lectures we use Zoom, and for practice we use Codeforces. Both will be live, so you can ask questions during the lecture and during the practice, the teacher will help you if you are stuck with your code or didn't get something. The lectures and the problem statements are in English. The school is mostly for Codeforces division 2 and 3 participants. You are required the knowledge of high school math and the ability to code simple programs in C++/Java/Python (or any other language that Codeforces supports, but we are not sure we can help with them).

The main topics are:

• Algorithms, Complexity, O-notation, Recursion
• Sorting and Binary Search
• Dynamic Programming
• Graphs, DFS, SCC finding
• Graphs, Shortest paths, BFS, Dijkstra's algorithm
• Strings, Prefix-function, Z-function
• Segment Tree

The main topics will be covered for sure, but other topics on the official website can be changed depending on average level of students. If you already attended our camps before, be careful, this one will contain the same topics.

Our tutors: VArtem, niyaznigmatul, Aksenov239, GShark, budalnik.

The cost of participation is 245 Euro. ITMO Official Certificate will be given to the participants.

To apply, visit https://schools.itmo.ru/en/school/26/. Application deadline is December, 15, 2021.

If you have any organizational questions (regarding documents, payment, certificates, etc) ask the school manager Ekaterina Rassolenko by emailing to e.rassolenko (at) itmo.ru.

We are aiming that there will probably be two learning groups, at different times of day, for students from different timezones. The current plan is: Morning classes are held from 11:00 to 15:00, evening classes – from 17:00 to 21:00 (GMT +3).

Hello Codeforces!

On Dec/01/2021 17:35 (Moscow time) Educational Codeforces Round 118 (Rated for Div. 2) will start.

Series of Educational Rounds continue being held as Harbour.Space University initiative! You can read the details about the cooperation between Harbour.Space University and Codeforces in the blog post.

This round will be rated for the participants with rating lower than 2100. It will be held on extended ICPC rules. The penalty for each incorrect submission until the submission with a full solution is 10 minutes. After the end of the contest you will have 12 hours to hack any solution you want. You will have access to copy any solution and test it locally.

You will be given 6 or 7 problems and 2 hours to solve them.

The problems were invented and prepared by Adilbek adedalic Dalabaev, Vladimir vovuh Petrov, Ivan BledDest Androsov, Maksim Neon Mescheryakov, Roman Roms Glazov and me. Also huge thanks to Mike MikeMirzayanov Mirzayanov for great systems Polygon and Codeforces.

Good luck to all the participants!

UPD: Editorial is out

Hi, Codeforces!

We are DELTIX. Founded in 2005, DELTIX is one of the market leaders in software development for financial research and products for systematic and algorithmic trading. In 2020 DELTIX joined the EPAM family. Our mission is to turn promising ideas into breakthrough products fast.

We are experts in:

• aggregation, storage, and processing large volumes of time-series data
• data modeling
• testing and deployment of quantitative models

In our team we value such skills as:

• knowledge of algorithms
• high-performance coding
• low latency data streams processing

We are excited to announce that we have released TimeBase Web Admin Community Edition.

More about DELTIX

Throughout the year, once per quarter, we will be inviting you to join DELTIX rounds at Codeforces. Today, we are excited to welcome you to the third installment of our rounds (joined Div1 и Div2) Deltix Round, Autumn 2021 (open for everyone, rated, Div. 1 + Div. 2), that will start on Nov/28/2021 17:35 (Moscow time). It is an open and rated round for both divisions.

We have prepared the following trophies for you:

1st place: Samsung Galaxy Z Flip3
2nd place: Samsung Galaxy Tab S7+
3rd place: Samsung Galaxy Watch4
1-100 places: branded t-shirts

Another 100 t-shirts will be distributed randomly between participants outside the top-100 but within the top-1000 and who participated in rated Codeforces rounds before.

Problems, except the last one, have been prepared by members of our team: Vladik, 4llower and AleXman111.

We would like to say a word of appreciation to:

• KAN and budalnik for the round management
• extra thanks to budalnik for creating one of the problems
• all the testers: Sugar_fan, 244mhq, Geothermal, andrew, aSmallTyphoon, _Time_Lord_, Hec, GustavoMG, phattd, ptd, kartel, bkbtpout, avoronoi, fixikmila, kartikeyasri23, Whiplash99, Ghazoo, Jon, asitnikoff, Zayadi, Ahmad7_7, Omar_Elaraby, Kart, Java and anegelytor.
• and also MikeMirzayanov for Codeforces and Polygon systems

We will offer participants 8 problems and 150 minutes to solve them. We wish everybody good luck and high ratings!

Fill out a short contact form if you are interested in employment opportunities or would like to speak with recruiters or members of our team.

UPD: The scoring distribution is 500 — 1000 — 1500 — 2000 — 2750 — 3000 — 3250 — 3750.

Thank you all for participating! (editorial)

Congratulations to the winners:
1. tourist
2. DmitryGrigorev
3. xtqqwq
4. Maksim1744
5. VivaciousAubergine
6. maroonrk
7. jiangly
8. heuristica
9. QAQAutoMaton
10. PubabaOnO

We were especially delighted with the result tourist, who was able to solve all 8 problems, congratulations!

Hello, Codeforces!

On Nov/26/2021 14:15 (Moscow time) Codeforces Round 757 (Div. 2) will start. This round will be rated for participants with a rating less than $$$2100$$$.

All the problems were authored and prepared by vaaven and me.

You will be given $$$5$$$ problems, one of which has two subtasks. You will have 2 hours to solve them.

We would like to thank everyone helped a lot with round preparation:

• First of all, errorgorn and phyzzmat for help with translating the terms into English.
• Aleks5d and KAN for excellent coordination.
• Ormlis, kostia244, errorgorn, Ziware, Makcum888, wxhtzdy, fishy15, Sprdalo, Riladavin, Ekler, FairyWinx, olya.masaeva, LetterC67, vasilykuzmin22, TheEvilBird, kartikeyasri23, Kolychestiy, KasenIbaraki, kuertov and WinCrash91 for testing and useful feedback.
• MikeMirzayanov for great Codeforces and Polygon platforms.

Score distribution: $$$500$$$ — $$$750$$$ — $$$1500$$$ — $$$(1500 + 1000)$$$ — $$$2750$$$.

Good luck everyone!

UPD: Editorial