Hello Codeforces!

On Nov/24/2023 17:35 (Moscow time) Educational Codeforces Round 158 (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, 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

Hello, Codeforces!

From the ICPC 2023 World Finals, we are happy to bring you an exciting online event: The ICPC 2023 Online Challenge powered by Huawei，which will start on November 20, 2023 15:00 UTC (UTC+8)

In this Challenge, you will have a unique chance:

• to compete with top programmers globally
• to solve 1 exciting problem prepared by Huawei
• to win amazing prizes from Huawei!

It is an individual competition.

The ICPC 2023 Online Challenge powered by Huawei:

Start: November 20, 2023 15:00 (UTC+8)

Finish: December 4, 2023 15:00 (UTC+8)

We hope you'll enjoy this complex yet very exciting Challenge!

Problem

We are glad to propose to you an exciting challenge “Deterministic Scheduling for Extended Reality over 5G and Beyond”, which is prepared by Huawei Wireless Product Line.

In this contest, we focus on a XR-service scheduling problem to maximize the total number of successfully transformed XR-data frames under specific transmission requirements. Extended reality (XR) is an umbrella term for different types of realities such as virtual reality (VR), augmented reality (AR), and mixed reality (MR), which can provide people with immersive experience. To achieve better user-experience, scheduling algorithm should be proposed to efficiently utilize the limited radio resources, e.g., time resource, frequency resource, and power resource. Due to several practical constraints, the scheduling task is a typical NP-hard problem.

Prizes from Huawei

Challenge Rules and Conditions

By participating in this Challenge, you agree to the Challenge Rules and Conditions of Participation

Good luck, we hope this will be fun!

Hello, Codeforces!

BULLMCHOW and I are glad to invite you to Codeforces Round 910 (Div. 2), which will start on Nov/19/2023 17:35 (Moscow time). You will be given 6 problems and 2 hours to solve them.

The round will be rated for participants of Division 2 with a rating lower than 2100. Division 1 participants can participate unofficially.

All problems are invented and prepared by BULLMCHOW and me. Special thanks go to Sofija06 and NemanjaSo2005, our two most dedicated testers. We would also like to honor:

• prvocislo, wuhudsm, Marckess, MateoCV, Wibo, curly_braces, LucaLucaM, null0124, OAleksa, AlphaMale06, Firefrog418, and sahaun for testing this round and providing valuable feedback!
• IgorI for coordinating the round well!
• dario2994 for reviewing some of the problems as the coordinator of a previous round proposal.
• KAN for his contribution towards hosting the round.
• MikeMirzayanov for creating the Codeforces and Polygon platforms!

We are looking forward to your participation!

UPD1: The score distribution is $$$500 — 1250 — 1750 — 1750 — 2000 — 2500$$$.

UPD2: Editorial

UPD3: Congratulations to the winners!

1. hitonanode
2. Rubikun
3. femboy-wannabe
4. potato167
5. Golovanov399
6. A_G
7. AmazingTalker_Frank
8. Geothermal
9. StarSilk
10. Farhod

UPD4: Also, congratulations to the Div. 2 winners!

1. femboy-wannabe
2. Top2Greece
3. hoiii
4. KaiAngel
5. Nguyen_Mai_Huong
6. lunchbox
7. bobbilyking
8. y_x_c
9. supercambrian
10. MeGustaElArroz23

Hello, Codeforces! ☀️☀️☀️

We are glad to invite you to our second Div. 3 round, which will take place on Nov/17/2023 17:35 (Moscow time). The round will be rated for all participants with rating less than 1600.

You will be given 7 tasks and 2 hours 15 minutes to solve it.

The tasks were prepared by zwezdinv, meowcneil, EJIC_B_KEDAX, Sokol080808 and molney.

Remember, that only trusted Div. 3 participants will be included in official standings. To qualify as trusted participant you need:

1. Participate in at least five rounds (and solve at least one problem in each of them)
2. Do not to have a point 1900 or greater in the rating

We would like to thank:

• MikeMirzayanov for Polygon and Codeforces
• Coordinators Vladosiya and Gornak40 for excellent coordination
• ace5, pavlekn, 998kover, EternalAlexander, Rubikun for red testing
• Kihihihi, Be_dos, alex.kudryashov, makrav, exhausted, 74TrAkToR, turkhuu622, _LeMur_, beemax, sedev57, misorin for yellow testing
• azureglow, Alex239, SashaT9, Pa_sha, goncharovmike for purple testing
• zarubin, OR_LOVe, TimVen74, ivan.alexeev, krigare, marzipan, Algolagon, Apachee, EzikBro, null0124, KoT_OsKaR, micho, keroru, dasha..zhilina for blue testing
• ilqw, El_Gemmy for cyan testing
• Flash700 for gray testing

Good luck everyone!

UPD: Editorial

Big greetings, Codeforces!

I am happy to invite you to Codeforces Round 908 (Div. 1), Codeforces Round 908 (Div. 2), which will be held on Nov/07/2023 17:35 (Moscow time).

This round will be rated for everyone. In both divisions, you will be given 5 problems and 120 minutes to solve them. All problems were cooked by me (sevlll777).

The traditional thanks-list to everyone who took part in the creation of the round. Thanks,

• 74TrAkToR for incredible coordination!

• gzchenben, Gary2005, SomethingNew, Sugar_fan, FairyWinx, EternalAlexander, RUSH_D_CAT, rsj, Kieray, CtrlAlt, Vladithur, nnv-nick, AndZhi, p_b_p_b, Adam_GS, tem_shett, 127.0.0.1, a.nasretdinov, Suiseiseki, Aokana, noimi, Psychotic_D for testing the round.

• CtrlAlt for help with polishing the statements.

• MikeMirzayanov for Polygon and Codeforces platforms.

I hope you will like the problemset and ideas hidden in the problems! It's guaranteed that statements are understandable, short, and, of course, ✨ stylish ✨.

Have fun!

Score Distribution:

Div. 1: $$$500$$$ — $$$1000$$$ — $$$1250$$$ — $$$2250$$$ — $$$2750$$$

Div. 2: $$$500$$$ — $$$750$$$ — $$$1500$$$ — $$$2000$$$ — $$$2250$$$

UPD: Editorial

UPD2: Congrats to the chAAAmpions!

Div.1:

1. maroonrk

2. Ormlis

3. Um_nik

4. tourist

5. 5sb

6. Swistakk

7. jiangly

8. Radewoosh

9. ethening

10. hank55663

Div.2:

1. Redpo

2. shenzihan

3. lq5

4. zookeeper780

5. omsincoconut

6. vishav_mehra

7. menezesd2

8. darling51707

9. kanao_enjoyer

10. bleeding

Hello Codeforces!

On Nov/03/2023 17:35 (Moscow time) Educational Codeforces Round 157 (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, Ivan BledDest Androsov, Maksim Neon Mescheryakov, Artem Ferume Ilikaev, Ruslan AcidWrongGod Kapralov, Alexey ashmelev Shmelev, Alex fcspartakm Frolov, Dmitry DmitryKlenov Klenov, Dmitry dmitryme Mescheryakov, Elena elena Rogacheva and me. Also, huge thanks to Mike MikeMirzayanov Mirzayanov for great systems Polygon and Codeforces.

Please note that the problems of this round partially intersect with the problems of the Southern and Volga Russian Regional Contest. If you took part in that contest, please refrain from participating in the round.

Good luck to all the participants!

Our friends at Harbour.Space also have a message for you:

BIMBA Y LOLA has partnered with Harbour.Space University to offer a Master's Degree scholarship in Computer Science, as well as work experience as a Junior Java Developer at the Development Team in BIMBA y LOLA.

At BIMBA Y LOLA, they understand the importance of counting on the most creative professionals, those with an enterprising spirit and passion for their work. They are seduced by talent, sensibility, initiative, an analytical nature, commitment to quality, a keen eye and a love for detail. And, of course, a clear vocation for fashion.

If you share these values, we are offering a young, dynamic and stimulating environment; one in which to progress and develop professionally; a company present in over 18 countries and embarked on an ambitious international expansion plan.

All successful applicants will be eligible for a 100% Tuition Fee Scholarship (29,900€/year) provided by BIMBA Y LOLA.

Requirements:

• Spanish and English language proficiency is a MUST
• Bachelor's degree in the field of Mathematics, Statistics, Data Science, Computer Science or similar

The candidate should be familiar with:

• Agile Methodologies (scrum)
• GIT
• Java 8/11+
• Spring
• Maven
• JUnit
• Mockito
• UML
• HTML
• CSS
• Javascript
• ReactJS
• SQL Server/MySQL

Desirable skills:

• Azure
• Azure DevOps — Pipelines
• Docker
• Kubernetes
• Helm
• Jira
• Confluence

Apprenticeship Summary:

• 100% Tuition Fee Scholarship to study a Master’s Degree in Computer Science for one year.
• 4 hours/day internship on campus.
• Competitive compensation.
• Opportunity to join the company full-time after graduation.
• Please note that preselected candidates will be requested to pay a non-refundable Application Fee of 125€ for assessment.

Candidate’s commitment:

• Study Commitment: 4 hours/day
• ‍You will complete 15 modules (each three weeks long) in one year.
• Daily class workload is 3 hours, plus homework to complete in your own time.
• Work Commitment: 4+ hours/day

Immerse yourself in the professional world during your apprenticeship. You’ll learn from the best and get to apply your newly acquired knowledge in the field from day one.

UPD: Editorial is out

Hello, Codeforces!

max0000561, a.nasretdinov and I are glad to invite you to our Codeforces Round 907 (Div. 2), which will be held on Oct/30/2023 17:35 (Moscow time). The round will be rated for all the participants with rating strictly less than 2100.

On behalf of our team, I want to thank:

• Coordinator 74TrAkToR for invaluable help in preparing the round.
• Testers maomao90, LeoPro, SomethingNew, maks_matiupatenko, max0000561, yaroslav_n, glebustim, Vash_nick, Murinh0, Topperoo, Alarick, priyanshu.p, Greg908, buffering, ventilator13, medved, zwezdinv, Rodionno for high-quality testing of the round and useful feedbacks!
• medved for excellent translations of the problems into English.
• MikeMirzayanov for amazing Codeforces and Polygon platforms.

And special thanks to my friends who have made a huge contribution to this round: Amir a.nasretdinov Nasretdinov, Maksim max0000561 Krylykov and Tanya medved Medved. Also thank you for all four years of friendship:)

During the round you will need to solve 6 problems. You will have 2 hours to solve them.

Score distribution: $$$500-750-1000-1500-2000-2250$$$

Good luck and, please, read the statements of all problems!

UPD: Editorial is out.

UPD 2: Congratulations to the winners!

Div. 1:

• neal
• arvindf232
• kotatsugame
• maspy
• Geothermal

Div. 2:

• ETO
• MikeMirzayakahashi
• stklight
• win1919810
• Little_Leaf

Hello, Codeforces!

waaitg, Cocoly1990 and I are glad to invite you to Codeforces Round 906 (Div. 1) and Codeforces Round 906 (Div. 2), which will take place on Oct/28/2023 17:35 (Moscow time). In both divisions, you will be given 6 problems and 2 hours and 30 minutes to solve them all. Note that one of the tasks is split into two subtasks.

We would like to thank:

• TheScrasse for his brand new coordination.
• KAN for the great help with round preparation.
• Alexdat2000 for Russian translation.
• errorgorn for his 1-year coordination and Monogon for his 2-year coordination of one problem.
• waaitg for donating his Dead by Daylight time to prepare the problems.
• errorgorn, Kubic, zhangjianjuncd, doroc, DoverHi, alwyn, Yakumo_Ran, AquaMoon, Vladithur, DrSwad, abc864197532, null_awe, irkstepanov, KAN, gamegame, tnaito, _irohasu_, uwu, Xylenox, Anonymous_Noob, GusFring, LRJf, SomethingNew, avi15 and gs20036 for testing the round and their invaluable feedbacks.
• Vladithur, errorgorn for their profound contribution in tests making.
• MikeMirzayanov for amazing platform Codeforces and Polygon.

Score distribution:

Div. 2: $$$500$$$ — $$$750$$$ — $$$1250$$$ — $$$2000$$$ — $$$(1250 + 2500)$$$ — $$$3250$$$
Div. 1: $$$750$$$ — $$$1250$$$ — $$$(750 + 1500)$$$ — $$$2000$$$ — $$$3500$$$ — $$$3500$$$

As always, wish you all get a non-negative delta in this round!

UPD1: Editorial

UPD2: congratulations to the winners!

Hello, Codeforces!

We are happy to invite you to our experimental round for three divisions, which will take place at Oct/22/2023 14:05 (Moscow time). Please note the non-standard start time for the round. Each division will have 5-7 tasks. The round will be held according to the Codeforces rules and will be rated for all three divisions. A few changes regarding the ratings of participants in this competition:

• In Div.3 the rating of participants is less than 1600.
• In the Div.2 ranking, participants range from 1600 to 2099.
• In Div.1 the rating of participants is no less than 2100.
• Please note that after Codeforces Round 904 (Div. 2) the rating will not be recalculated until the end of this competition.

Let us note that two team Olympiads will be held in parallel on this day and the rounds are based on their tasks:

• XXI Moscow Team Olympiad, high school students competition based in Moscow that is an elimination contest for All-Russian Team Olympiad.
• III Open Team Olympiad UMSh in programming.

We would like to thank everyone who helped me a lot with round preparation.

• Coordinators Artyom123 и Vladosiya for excellent coordination and useful advice.
• Problem authors 74TrAkToR, Mangooste, TheEvilBird, Tikhon228, teraqqq, valerikk, Dmitry07.
• Testers pavlekn, zwezdinv, plagues, SashaT9, Maks_Simenkov, orolik, tmari_sun, OR_LOVe, _why_not_, TimVen74, zarubin, myav, ctraxxd, Gassa, OAleksa, Acanikolic73, AndrewPav, AlphaMale06, NemanjaSo2005, dorijanlendvaj, defnotmee, meOwO, Umi, CIXTEEN, golions, MagentaCobra, FairyWinx, v0s7er, adepteXiao, induk_v_tsiane, Alexdat2000, Be_dos, mr.kolya, kevinxiehk, alexxela12345, talant, daubi for high-quality testing!
• MikeMirzayanov for amazing Codeforces and Polygon platforms.

We wish you good luck and high rating!

UPD: One of the problems will be interactive, so please read guide for interactive problems before the contest.

UPD: Score distribution:

• Div.3: $$$500-1000-1500-1750-2500-2750-(1750+2000)$$$
• Div.2: $$$250-500-1000-(750+1250)-2250-2750$$$
• Div.1: $$$(250+500)-750-1000-1250-2000-2750$$$

UPD: Editorial

UPD: We will retest the solutions to the problem div3F and div2C. This may make minor changes, the rating will be recalculated later.

UPD: Retesting took several minutes. Now all the results are correct :)