Codeforces! This is a special announcement!

Last year, we had a contest for Tech Scouts, our two week International Summer Camp of Science, Technology, Design and Leadership held in July. The top performers received a full tuition waiver to attend the camp free of charge!

This year, it’s on again — same rules, same prize...round 2. Are you ready?

What it is?

Harbour.Space University, the International Tournament of Young Mathematicians (ITYM) and St. Paul's International School Barcelona have designed a special online test for high school students, to take place on May 5th at 15.00 CET Time.

We’ve prepared it to test your level in both maths and computer science, and, similarly to last year, the top performers have a chance to win two weeks in Tech Scouts: our maths and computer science summer camp for gifted youth. The camp, created for high school pupils aged 12-18, will take place from the 8th to the 19th of July in Barcelona, Spain, and is taught entirely in English.

How it works?

You can take part in the online test if all the following conditions are met:

1. Between the ages of 12 to 18,
2. Have not graduated from high school
3. Eligible to take part in IOI/IMO 2020.

The top performers of the online contest will be invited for a personal interview to demonstrate understanding of the problems solved during the contest. After the test, the most successful performers will be interviewed and awarded a full tuition waiver to attend the advanced level of the Advanced Technical Track of Tech Scouts alongside the winners of ITYM and Catalan Olympiad of Informatics.

Tech Scouts is designed to lay out the foundation of knowledge in mathematics and computer science for the next phase of higher learning. During a two-week intensive training, the students will follow a college level curriculum and discover their passions by getting to know one of Europe’s leading institutions in technology, design, and entrepreneurship.

In order to register for the contest, please fill out this form before May 3rd, 2019. All participants of the contest will get a 20% discount link to attend Tech Scouts.

If you have any questions, please don’t hesitate to ask! If not, best of luck with the contest, and we hope to see you guys soon!

Until then, you can keep up with Harbour.Space by checking out our Instagram @harbour.space :)

Happy coding! Harbour.Space University

Hello Codeforces!

On May/01/2019 17:35 (Moscow time) Educational Codeforces Round 64 (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 7 problems and 2 hours to solve them.

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

Good luck to all participants!

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

Hi Codeforces!

Harbour.Space University, the International Tournament of Young Mathematicians (ITYM) and St. Paul International School Barcelona have designed a special online test for high school students, to take place on May 5^th at 15.00 CET Time.

You can take part in the online test if all the following conditions are met:

1. Between the ages of 12 to 18,
2. Have not graduated from high school
3. Eligible to take part in IOI/IMO 2020.

After the test, all participants will get a 20% discount link to attend Tech Scouts, the two-week summer camp we run from the 8^th-19^th of July in one of Barcelona's leading international schools, St.Paul’s, and the most successful performers will be interviewed and awarded a full tuition waiver to attend the advanced level of the Advanced Technical Track of Tech Scouts.

In order to register for the contest, please fill out this form before May 3^rd, 2019.

We would love to see you guys at our camp this year — if you’re interested in joining, or if you just want to know more, just head over to the Tech Scouts website.

UPD: There are some minor issues with one of the problems, we'll use one of lesser-known problems by Maxim Babenko.

Congratulations to the winners:

Congratulations to the best hackers:

And finally people who were the first to solve each problem:

UPD2: The editorial is out.

Hi all!

From April 30th to May 14th, Codeforces will host VRt Contest: the second contest organized by VeeRoute. VeeRoute is the developer of planning and management software for transportation and multimodal logistics.

Contest participants will have to solve an optimization problem where local optimization is challenging. The task is similar to those that VeeRoute has to solve regularly. Since the format is nothing like a standard Codeforces round, the contest will be unrated.

Participation

Everyone is welcome to take part in the contest. The consest is for individual participation, with no restrictions on age or division.

Prizes

• I place — 75 000 RUB (1155 USD)
• II place — 50 000 RUB (770 USD)
• III place — 25 000 RUB (385 USD)

Additionally, top 25 participants will get a VRt T-shirt.

Good luck to all participants, and have a great contest!

Hi Codeforces!

I'm so happy to invite you to Codeforces Round 556 (Div. 1) and Codeforces Round 556 (Div. 2)! The rounds will be held on Apr/29/2019 17:35 (Moscow time). The round will be rated for both divisions. (At least that's what I've been told!)

The problems were written and prepared by me. Thanks to 300iq for the round coordination, and to Radewoosh for his invaluable help with choosing the problemset and testing the problems! Also, I want to give a shout-out to MikeMirzayanov for his amazing Codeforces and Polygon platforms!

My browser's tab bar, right now.

You'll work on 5 problems, and you will have 2 hours to solve them. The scoring distribution will be revealed closer to the round.

def get_end_remark():
    return random.choice([
        "Wish everyone high ratings!",
        "Good luck!",
        "Have fun!",
        "Please, read all the problems!"])

UPD 1: The scoring distribution time!

Div 2: 500 — 1000 — 1500 — 2250 — 2750

Div 1: 500 — 1250 — 1750 — 2500 — 2750

Also, thanks to cdkrot, vintage_Vlad_Makeev and qwertyland who contributed to the round testing!

UPD 2: The round is over! Sorry for misbalancing the difficulties in Div2, it was totally unexpected for us. Meanwhile, you can have a look at the editorial!

UPD 3: We finished the system tests. Congratulations to the winners!

Div 1:

1. Um_nik
2. DearMargaret
3. maroonrk
4. Reyna
5. LHiC

Div 2:

1. jiangly
2. Simplicity
3. Netherdrake
4. C137
5. kobor

Also, a shout-out to the first solvers of each task!

Suddenly, this round will consist of 7 different problems also!

UPD2: The round will consist of 7 problems and one of them will be in easy and hard editions!

<almost-copy-pasted-part>

Hello! Codeforces Round 555 (Div. 3) will start at 26.04.2019 17:35 (Московское время). You will be offered 6 or 7 problems (or 8) with expected difficulties to compose an interesting competition for participants with ratings up to 1600. Probably, participants from the first division will not be at all interested by this problems. And for 1600-1899 the problems will be too easy. However, all of you who wish to take part and have rating 1600 or higher, 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. I tried to make strong tests — just like you will be upset if many solutions fail after the contest is over.

You will be given 6 or 7 (or 8) problems and 2 hours to solve them.

Note that the penalty for the wrong submission in this round (and the following Div. 3 rounds) is 10 minutes.

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

• take part in at least two rated rounds (and solve at least one problem in each of them),
• do 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.

Thanks to MikeMirzayanov for the platform, help with ideas for problems and for coordination of my work. Thanks to my good friends Mikhail awoo Piklyaev, Maksim Neon Mescheryakov and Ivan BledDest Androsov for help in round preparation and testing the round.

Good luck!

I also would like to say that participants who will submit wrong solutions on purpose and hack them afterwards (example) will not be shown in the hacking leaders table.

</almost-copy-pasted-part>

UPD0: I also would like to thank my friend Adilbek adedalic Dalabaev for helping me with understanding problems difficulty and other help with round preparation!

UPD1: Big thanks to dreamoon_love_AA, Ashishgup, Jeel_Vaishnav and love.zy for testing the round!

UPD3: Editorial is published!

UPD4:

Congratulations to the winners:

Congratulations to the best hackers:

And finally people who were the first to solve each problem:

Once again, TREMBLE BEFORE THE MIGHTY OMEGALULRIPGRAPE.

(He last walked the Earth in round 538 btw.)

Hello Codeforces!

We are here to invite you to Codeforces Round #554 (Div. 2), which will take place at Apr/24/2019 17:35 (Moscow time).

The round will be rated for all Division 2 participants (with rating less than 2100), yet any Division 1 participants are welcome to join us out of competition.

The round will be cat themed. Raise your paws and prepare your catnips!

(Or even cat memes, while you're at it).

You will be given 6+1 problems ( 6 problems, one of them has 2 subtasks ) to solve in 2 hours. The round's problems were prepared by Xuan-Quang xuanquang1999 D. Nguyen, Duy-Bach AkiLotus Le, Stefan stefdasca Dascalescu, Quang-Minh MofK D. Nguyen and our dear Codeforces coordinator Dmitry cdkrot Sayutin.

Gladly (or sadly), no interactive problem tonight!

Also, the tribute should be given to everyone within the team — we all make it possible:

• Andrew GreenGrape Rayskiy for various problem suggestions and the infamous OMEGALULRIP influence. ;)
• Xuan-Tung neko_nyaaaaaaaaaaaaaaaaa Nguyen for testing the rounds and various suggestions in the core theme idea. Nya~.

Last but not least, I want to give a huge appreciation to MikeMirzayanov for the awesome Codeforces and Polygon platform, which makes this contest possible.

P/s: I will be at the Discord CP Community to discuss the problems after the coding phase. However, please follow the rules and don't discuss the problems during the contest by any means.

Wish everyone good luck and high rating!

P/s(2): Commies united!

P/s(3): A dear thank-you to Grigory vintage_Vlad_Makeev Reznikov for the last-minute complete testing as well! ;)

UPD1a: Another comrade, Quang-Minh MofK D. Nguyen joined the fun! Kudos for the problem suggestion! ;)

UPD1b: The problemset contains 6+1 problems ( 6 problems, one of them has 2 subtasks ).

UPD2: Score distribution: 500-1000-1500-2000-2000-(2250+750).

UPD3: Editorial will be available tomorrow. Sorry for the waiting, we have quite a lot of things to polish. ;)

UPD4: The contest is finished. I hope that you're satisfied. And here come our winners ;)

Official participants:

1. hamzzq
2. davidHernandes
3. oiyoayao
4. abandonedw1
5. OnionGod
6. IPL
7. memset_inf
8. dsgsjk
9. FluffyT (the only official participants solved F1+F2, too bad she didn't solve E :<)
10. _wxw_

Div.1 + Div.2 participants:

1. dreamoon_love_AA (solved all problems!)
2. pwild
3. Sugar_fan
4. hamzzq
5. natsugiri
6. kmjp
7. davidHernandes
8. Jeffrey
9. betrue12
10. KrK

UPD5: Editorial blog post is available.

Hello Codeforces!

On Apr/22/2019 17:35 (Moscow time) Educational Codeforces Round 63 (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 problems and 2 hours to solve them.

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

Good luck to all participants!

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

Hi Codeforces!

This summer, we want to invite you to Tech Scouts, the two-week summer camp we run from the 8^th-19^th of July in one of Barcelona's leading international schools, St.Paul’s.

This camp, divided into Creative and Technical tracks, is designed to lay out the foundation of knowledge for high-school students in the fields of technology, mathematics, business and design. Both tracks are taught in English.

We would love to see you guys at our camp this year — if you’re interested in joining, or if you just want to know more, just head over to the Tech Scouts website.

This camp is for anyone passionate about tech or design, so if you know someone who might be interested, be sure to let them know too!

Ps. Don’t wait too long — you still have an early bird discount, but only until May 20^th

UPD: The round will contain 6 problems.

Congratulations to the winners:

Congratulations to the best hackers:

And finally people who were the first to solve each problem:

UPD: The editorial is out

Hi Codeforces!

I'm excited to announce the Forethought Future Cup! It will consist of two rounds, an online round on April 20th, 11:05am PDT, and an onsite round on May 4th, 10:05am PDT. Both of these rounds will be rated and open for all participants. The top 25 local contestants near San Francisco will be invited to the Forethought office to take part onsite.

Each round will be a combined round. In the first round, there will be 8 problems in 2.5 hours. There will be at least one interactive problem in this round. Please read the interactive problem guide if you haven’t already.

The problems in this round were all written by me. Thanks to ismagilov.code, mohammedehab2002, Jeel_Vaishnav, Learner99, dojiboy9, vlyubin, y0105w49, KAN, arsijo for testing and coordination. Of course, thanks to MikeMirzayanov for Codeforces and Polygon, and for allowing us to host the round.

Prizes

T-shirts will be awarded to all onsite participants. 25 shirts will also be randomly awarded to contestants in the elimination round with ranks 1 to 250. The onsite round will also have some monetary prizes:

• First: $500
• Second: $250
• Third: $100
• 4th — 10th: $50

About Forethought:

At Forethought, our mission is to use AI technology to augment human abilities and make everyone “a genius at their job”. Our main product is Agatha, an assistant that helps customer support agents answer cases more quickly and confidently by suggesting answers and triaging cases. We've raised over $10M in VC funding and were the winners of 2018 SF TechCrunch Disrupt Battlefield.

I joined Forethought back in December 2018. We are a small 12 person startup, and have a lot of competitive programmers on our team, including me, y0105w49, vlyubin, and dojiboy9 (our CEO, who is also an ICPC World Finals Judge). I’m happy to answer any questions about working here in the comments below or through PM.

We’re hiring! Please fill out this form if you are interested.

Updates

UPD 1 The scoring distribution will be 500-1000-1500-2250-2500-3250-3250-3750

UPD 2 Tutorial can be found here: https://codeforces.com/blog/entry/66639

UPD 3 Congratulations to the top 5!

1. tourist
2. Benq
3. Radewoosh
4. yutaka1999
5. ainta

Hi, Codeforces!

Codeforces Round #553 (Div. 2) will be held on Apr/18/2019 18:35 (Moscow time). Round will be rated for second division (rating below 2100). As usual, participants from the first division can participate in the contest out of competition.

My gratitude to arsijo and KAN for coordinating the round, Markellonchik (special thanks for the help in preparing one of the tasks), mohammedehab2002, Jeel_Vaishnav for testing, and also 300iq for the idea and preparation of one of the tasks, Aleks5d and isaf27 for testing it, and of course MikeMirzayanov for Codeforces and Polygon systems.

In this round you will help the residents of the Kingdom of Kremland. I strongly recommend you to read the statements of ALL tasks (and of course, try to solve them).

Good luck!

UPD: Scoring distribution: 500-750-1250-1750-2250-2750.

UPD: Editorial

UPD: Thank you for your participation in this round! Congratulations to the winners!

Div. 2

1. square1001
2. hitonanode
3. jaguar1996
4. Mofk_wont_2k8
5. sansen