By Ripatti, 8 years ago, translation, In English,

Hello everyone!

I am glad to welcome you on today round of Codeforces. I hope that recent color revolution and a more later time for start of round will make some variety into process of solving problems:)

An author of today problems is me. RAD helped me to prepare this round, Delinur translated statements into English.

Good luck.

UPD.

The round ended, ratings was updated.

Winners of div1:

1. Egor

2. tourist

3. unicef

4. sevenkplus

5. ivan.popelyshev


Winners of div2:

1. RainbowDash

2. cjtoribio

3. miraliv

4. adrianoo

5. majia5

Yippee!

Editorial.

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By RAD, 8 years ago, translation, In English,
Hi

Unfortunately, Codeforces Beta Round #93 is rescheduled for tomorrow because of circumstances beyond our control. The new time is November, 9, 21:00 Moscow time (exactly 24 hours ahead).

We apologize for any inconvenience.
 
See you tomorrow,

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By Nickolas, 8 years ago, translation, In English,

Every time I win a trip to any kind of tournament onsites (so far this happened three times, so I can generalize), I find myself facing a serious problem, named "souvenirs". I've settled this question once and for all as long as it concerns myself: the best souvenir is a pile of photos accompanied by a thrilling story. The second-best is a couple of Swiss chocolates, though I can handle both at the same time :-) But one can't live in a society and be free of it; and it's the souvenirs for people around me that become a real problem.

Take, for example, my last year's trip to Las Vegas. I went there with a t-shirt demand from my future husband's sister. Besides, my future husband himself stayed at home (his visa application was unexpectedly refused, and there's not much point in winning a trip without the visa), and I felt I had to bring him something to cheer him up. So my shopping plans were quite intense.

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By MikeMirzayanov, 8 years ago, translation, In English,

Hello!

Today is November 7th. And this, as you probably know, is a very special day for many ex-USSR citizens. Many years ago on this day the Great October Socialist Revolution happened. I still remember red flags and military equipment on the avenue and the feeling of common joy and holiday. But today, in 2011, we have another revolution — the Codeforces revolution of colors and titles. Hooray!

So, over the last few months our community has grown significantly. If we count the users who have participated in the rated contests over the last 9 months at least once, at the beginning of the year they were 4330, and now — 7615. This is a great step forward! Of course, this leads to a dramatic rating inflation. Most of the ELO-like ratings have the same issue. For example, only A. Karpov had Elo chess rating of more than 2700 in 1979; however, there were as much as 15 people with such rating in 1994, and in 2009 they were 33. In 2001 there were less than 10 red players on TopCoder; in 2005 they were about a hundred and now — more than 250.

A similar effect occurred on Codeforces. It is particularly striking as it is accompanied by a marked audience growth. For this reason it was decided to change the color system . In addition, the record shows that not all participants liked the military ranks. Besides, they are quite far from our intellectual and sporting spirit. Today we will disband Codeforces as a military unit and introduce sport titles. We've mostly used the titles from intellectual sport games to work out the following classification:

Ratings Range Color Title Division
2600+ Red International grandmaster 1
2200 - 2599 red Grandmaster 1
2050 - 2199 Orange International master 1
1900 - 2049 Orange Master 1
1700 - 1899 Violet Candidate master 1
1500 - 1699 Blue Expert 2
1350 - 1499 Green Specialist 2
1200 - 1349 Green Pupil 2
0 - 1199 Gray Newbie 2

In addition, the rating recalculating formula was slightly fixed to slow down the inflation. Now the sum of ratings will not be the constant, but is likely to be slightly falling. In fact, the changes are cosmetic and will be visible only on a series of contests.

I understand that for some of you it will be hard to say good bye to the favorite color, but let's look ahead with optimism — new victories will bring the lost color back color and help to win the proud title of a Grandmaster!

MikeMirzayanov

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By aropan, 8 years ago, translation, In English,

"Tryam" to everyone!

I am an authors of the today's contest. First of all I want to thank Artem Rakhov [RAD] (thanks to him, you'll understand my problems) and Maria Belova [Delinur] (those who know my English level will understand a huge of my thanks). Also thanks to everyone staff for the wonderful of the codeforces system. And also thanks to Sergei Tarasov [Seryi] and Andrey Tkachenko [TBGame] for ideas generating and testing.

Good luck and have fun.

Today, a breakdown of score will be slightly different from the standard - for the second division is 500-1000-2000-2000-2500 and 1000-1000-1500-2000-2500 for the first.

And one more, but certainly pleasant news - register ends exactly at the start of the round.

Analysis problem.


How it was.
At 19:35 Moscow time reported that in pretests for 123B - Squares have errors (a special thank to him). Indeed, a special case was not considered (a = 1, b! = 1 and symmetric to it). We have made decision to exclude tests covered by this case. There were a lot of such tests in pretests. Test generator has been fixed, and all tests were changed. After that all submits have been rejudged. As a result some submits with WA verdict could get the AC and vice versa.

What we have now.
We believe that the round should be rating. But if the situation with the problem 123B - Squares is strongly influenced to you, you can send an appeal with the evidence of this in the form of a personal message to RAD no later than 11pm on November 4. We can either do this round unrated for you or remove excess submits.
At the end of the system testing rating will be updated. If you have no appeals, it will be your final rating.

Sorry for the inconvenience.

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By MikeMirzayanov, 8 years ago, translation, In English,

Hello!

Informal contest Codeforces Testing Round #2 is scheduled on 10/29/2011 01:00PM (UTC). We will test the latest innovations on Codeforces that they do not affect the contests. If not, we will fix it quickly :) So, this round will take place "as is", no warranty about it.

Problems for the round may be famous to someone, but I'll try to make them such not for any of you. It will be about 4 problems, as quite simple and something more tricky.

I say thanks in advance to all those who will come and test the system. Thank you!

The contest moved to start on 10/29/2011 01:00PM (UTC) (it has been announced to start on other time, be careful).

It will be unrated round.

Thank you all for your help. I think it turned out pretty fun for you and useful for us!

MikeMirzayanov

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Announcement of Codeforces Testing Round #2
Announcement of Codeforces Testing Round #2
 
 
 
 
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By witua, 8 years ago, translation, In English,

Hello!

Wellcome to Codeforces Beta Round #91! This time, the author of the round will be me, Herasymiv Vitaliy (witua). Thanks a lot to Artem Rakhov (RAD) for helping in round preparing and Maria Belova for problems translation. I hope you will like problems.

Good luck!

Thanks all! And here are the winners:

Division 1:

  1. tourist
  2. Rizvanov
  3. kuniavski
  4. Petr
  5. vepifanov
  6. dzhulgakov
  7. e-maxx
Division 2:

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By MikeMirzayanov, 8 years ago, translation, In English,

Hello!

Today, October 23 (Sunday) at 08:00 (UTC) will begin online contest based on recently completed ACM-ICPC NEERC Southern Subregional Programming Contest 2011. Two days ago a competition was held in Saratov (hosted by Saratov State University), but today you can participate in it informally. Onsite participants will in the standings, to give you an oppotunity to compare your results with onsite teams. The statements will be available as a PDF-file and in HTML. To participate, go to the site http://acm.sgu.ru.

After the contest, you may discuss here the problems. I hope you'll like them.

Chairman of the Jury,
MikeMirzayanov

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By Nerevar, 8 years ago, translation, In English,

The X regional school team programming contest will be held in Saratov on Tuesday, 18 of October. The jury has prepared a set of interesting problems. We came to conclusion that it will be unfair if these tasks are available only for the onsite school teams. That's why we decided to organize a contest with these tasks on Codeforces.

The contest starts at 10.30 MSK (half an hour later than the start of the school contest: it is done to give the organizers some time to ensure that everything goes well) and will last 5 hours. The rules of the contest are official ACM ICPC rules. Both teams and individual participants are allowed to take part in it. For individuals the contest will be rated. Registration will be open until the end of the contest.

The contest was prepared by members of the best teams of the Saratov State University: Gerald Agapov, Polina Bondarenko, Ivan Fefer, Artem Rakhov, Nickolay Kuznetsov, Edvard Davtyan, Pavel Kholkin and Igor Kudryashov, as well as by our "veterans": Natalia Bondarenko, Michael Mirzayanov and me, Dmitry Matov. Maria Belova also did an excellent job and translated the statements into English. 

Enjoy the contest!

The statements will be available as PDF via links:

It will be file input-output in these problems. Read statements carefully.

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By Serega, 8 years ago, translation, In English,

Hello everyone!

Welcome to the Codeforces Beta Round #90! I (Sergey Sukhov) and Alexander Ignatyev (dudkamaster) have prepared for you today's contest. We thank Artem Rakhov (RAD) for help and useful hints, Mariya Belova (Delinur) for translation of statements, as well as Michael Mirzayanov (MikeMirzayanov) for opportunity to conduct this round.

Good luck and high rating!

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Announcement of Codeforces Beta Round #90
Announcement of Codeforces Beta Round #90
 
 
 
 
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