Hello, Codeforces!

I'd like to invite you to Codeforces Round #375 (Div. 2). It'll be held on Monday, October 3 at 14:35 MSK and as usual Div. 1 participants can join out of competition. Note that round starts in the unusual time!

This round is held on the tasks of the school stage All-Russian Olympiad of Informatics 2016/2017 year in city Saratov. They were prepared by me and Mike Mirzayanov (MikeMirzayanov).

Great thanks to Gleb Evstropov (GlebsHP) for helping me preparing the contest and for the idea of the most tricky problem, which was specially made for this round, to Tatiana Semenova (Tatiana_S) for translating the statements into English and to Nikolay Kalinin (KAN) for writing solutions and very helpful advices.

It will be a little unusual round — you will be given six problems and two and half hours to solve them.

Score distribution 500-1000-1500-2000-2500-3000. Good luck everyone!

UPD Editorial

A quick update on the status of e-maxx translation project.

First, I'm excited to announce that I've joined e-maxx in English team as an admin! From practical point of view this means that I can review and accept pull requests and help with the issues arising during the contribution process. Feel free to contact me if you have questions. And if I encounter anything outside of my expertise, I can always ping RodionGork directly :-)

Second, October is a particularly good month for contributions to e-maxx translation, as well as for open source contributions in general. Hacktoberfest is back this year, and they are giving away t-shirts to anyone who makes 4 pull requests to any GitHub-hosted projects between October 1st and 31st.

We don't have an explicit list of issues to work on, but there are two basic kinds of contribution we're looking for:

1. Translations of articles (obviously :-)).
2. Practice problems for already translated articles — these are the problems at online judges on which the described algorithm can be practiced. See circle-circle intersection article for an example.

Here is a recent post by RodionGork about technical improvements in contributions process.

So if you have at any point considered contributing to e-maxx translation, now is the time to do it :-)

ACM-ICPC World Finals Reunion Dinner was on 16th of September in the Stanford University. Vladimir Yakunin, the participant of ICPC 2005 and 2010, engineer of Google, shared his impressions about this meeting:

The organizer, Doug Mohr, invited us to one of Stanford buildings. Yet on the parking I met Roman Chadnov, my friend from Tomsk. We entered the building and asked where the event was. It turned out that there were several of them. Finally we found out the garden mainly thick of young people in jeans and t-shirts who got together and didn’t pay attention to others. Many of them had badges of Google and Facebook members. Our!

In the far end of the garden there was a bar which, however, was not so popular. Waiters scurried about the programmers and offered various snacks (mmm, tunny was amazing!!!). All people fastened on their badges (actually not to make the acquaintance of everyone) and sorted out, apparently, according to linguistic/geographical features. Russian group quickly became too much and divided into two. Also there were more than one Chinese group.

Apart from expected friends (Andrey Lasarev, Artem Rahov and Sergei Rogulenko from Saratov; Slava Isenbaev, Roman Elizarov, Dmitriy Dgulgakov and others) I surprisingly met several people who also take part in ICPC: Ilya Mironov — Vice World Champion of 1998, a colleague from Google and well-known in narrow circles player in the «What?Where?When?».Alex Grusheckiy who sits in 10 meters away from me at work, also was among them. Of course, you can guess that the team from Vitalik Goldstein and Petit Mitrichev coincidentally is not gathering.

Andrey Lasarev, Vladimir Yakunin, Alex Grusheckiy

Intel Code Challenge Elimination Round will take place on Saturday, 1 October 17:05 MSK. Only russian citizens from 18 to 27 years old can officially participate in this competition.

However, for all other users of the Codeforces it will be an usual round. The round will be rated and both divisions can participate.

There will be 6 problems and 2 hours to solve them. Scoring distribution will be announced closer to the start of the round.

The problems were prepared by me — Vladislav Epifanov (vepifanov). I want to say thanks to Alexey Shmelev (ashmelev), Alexander Fetisov (AlexFetisov) and Vladislav Isenbaev (winger) for testing the problems, coordinator of the Codeforces Gleb Evstropov (GlebsHP) for his help with the contest preparation, and Mike Mirzayanov (MikeMirzayanov) for the Codeforces and Polygon systems.

UPD. Scoring: 500-500-1000-1500-2000-2500.

UPD 2.

I must apologies for the problem C. We decided to simplify it in the last moment, and it turned out, that the simplified version of it already appeared on another online judge.

Anyway, I hope that the second round will be better than the first one.

Editorial for this round will be published on Sunday, 2 October.

UPD 3. Editorial

Hello, Codeforces!

30th September 2016 at 17:05 MSK Codeforces Round #374 (Div. 2) will take place for second division participants. Traditionally, participants from the first division will be able to join out of competition. Please, notice that the start time is unusual.

This is my second Codeforces round, I tried to make problems interesting for everyone, so I recommend to read all problems statements! I hope that everyone will find something new and interesting. I wish lots of accepted runs and higher rating to all participants.

I want to thank Michael MikeMirzayanov Mirzayanov for wonderful platforms Polygon and Codeforces, and for help in preparing the problems, my best friends Danil danilka.pro Sagunov also for help in preparing the round and Ivan BledDest Androsov for testing the problems.

Participants will be given five tasks and two hours for solve them. Scoring system will be announced traditionally closer to round start. :)

The scoring is almost the standard: 500-1000-1500-2000-2750

UPD: Editorial

Welcome to 2016-2017 CT S03E04: Codeforces Trainings Season 3 Episode 4. The training duration is 4.30 hours. It is opened for teams as well as for individual participants. After the end you may use the practice mode to complete problem solving. Also it will be available as a virtual contest for whose of you who can't take part today. Please, do not cheat. Only fair play!

Visit Codeforces::Gym to find the contest and register.

We are planning to start on September, 28, 2016 13:10 (UTC).

It is possible that the problems will be too easy for some participants, it is possible that we will add some problems.

Good luck!

Hello everyone,

Several people are asking me when A2 Online Judge is coming back, and unfortunately the issue this time might take longer to fix it.

This is the server which was hosting the website in my garage for several years:

And I think it's time to move to the cloud, but this requires some money. I created a campaign to raise $3000 which I need to host it on AWS for the next 3 years at least. You can read more details here: https://www.gofundme.com/support-a2oj

Please support to bring the website back, even if by just sharing the campaign.

Thanks in advance,

Ahmed Aly