Petr's blog

By Petr17 hours ago, In English
 
 
 
 
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By Petr27 hours ago, In English
 
 
 
 
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By Petr28 hours ago, In English

I’ve talked about a problem from today’s dress rehearsal in http://petr-mitrichev.blogspot.com/2012/05/world-finals-day-2-upe-dinner.html

Here’s the first tough testcase for it: http://petr-mitrichev.blogspot.com/2012/05/power-towers-problem-testcase.html

Good luck! :)

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By Petr29 hours ago, In English
 
 
 
 
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By Petr39 hours ago, In English
 
 
 
 
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By Petr40 hours ago, In English
 
 
 
 
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By Petr3 days ago, In English
 
 
 
 
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By Petr4 days ago, In English
 
 
 
 
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By Petr4 weeks ago, In Russian

Завтра не буду участвовать во втором раунде КРОКа, так как и сам второй раунд, и финал пересекаются с другими делами, спланированными до объявления КРОКа. В случае финала это ch24, о котором было даже известно “олимпиадному сообществу” заранее :) Впрочем, этот вопрос уже обсуждался в теме про КРОК, а хочу я сказать следующее:

Было бы круто расписание всех соревнований объявлять хотя бы месяца за три до первого раунда. Мне кажется, это должно принести пользу как кодефорсес (больше времени на подготовку раундов, больше времени выбить из спонсоров еще денег :)), так и спонсорам соревнований (больше времени на общение с участниками, больше времени логотип на главной), не говоря уже об участниках. А?

Всем удачи завтра!

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By Petr5 weeks ago, In English

There’s a live interview with me, tomek, Onufry Wojtaszczyk and Bartholomew Furrow in 25 minutes: https://plus.google.com/u/0/101571483150813305324/posts/DxaiBoikC8N

UPD. The interview is postponed, I’ll write about new date and time :)

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By Petr2 months ago, In English

Before systest:

  1. tomek, problems 1 and 2.
  2. Petr, problems 1 and 2.
  3. Jacob, problem 3.
  4. romanandreev, problem 2.
  5. ACRush, problem 2.
  6. tomekkulczynski, problem 2.
  7. jakubr, problem 2.
  8. RAVEman, problem 2.
  9. Somebody, problem 3.
  10. gawry, problem 1.
  11. hos.lyric, problem 1.
  12. ilyakor, problem 2.
  13. iwiwi, problem 3.
  14. Po-Ru Loh, problem 1.
  15. vepifanov, problem 2.
  16. cerealguy, problem 1.
  17. pparys, problem 1.
  18. sdya, problem 1.

After systest:

  1. romanandreev, problem 2.
  2. tomek, problem 1.
  3. ACRush, problem 2.
  4. gawry, problem 1.
  5. hos.lyric, problem 1.
  6. Petr, problem 2.
  7. cerealguy, problem 1.
  8. pparys, problem 1.

Congrats romanandreev!

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By Petr4 months ago, In Russian

На открытии сборов в Петрозаводске были вручены награды "Итоги года 2011" SnarkNews и "Медаль Кормена 2011" Codeforces. Вот запись церемонии: http://youtu.be/x1PkKIHSB_M?hd=1

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By Petr8 months ago, translation, In English
Tags tco
 
 
 
 
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By Petr12 months ago, In English
As usual, I'll be doing live commentary on the World Finals on http://petr-mitrichev.blogspot.com/. Here are some pictures to get started.

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By Petr16 months ago, In English
 
 
 
 
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By Petr23 months ago, translation, In English
Here's a problem that has appeared at a recent contest: We are given a 7 times 7 field where some of the cells have numbers between 0 and 8, inclusive, and all remaining cells have dots. We want to find such allocation of exactly 10 stars to the cells with dots, at most one star per cell, so that each cell with a number has exactly that number of stars in its 8 adjacent cells. Moreover, we will only consider such 7 times 7 fields where such allocation of 10 stars exists and is unique.

Can you create a testcase for this problem that will kill backtracking solutions? It seems pretty hard to do at such small field, but it is possible!

Here are the official rules of this challenge: http://killbacktrack.appspot.com/rules.jsp.
And here's the website where you can test your testcases, which also keeps a scoreboard: http://killbacktrack.appspot.com/.

I've got a pretty good testcase, but I don't want to reveal it yet :) Please tell if there's some problem or possible improvement to the website.

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By Petr2 years ago, In English
You can find my impressions about beta round 2 in my blog: http://petr-mitrichev.blogspot.com/2010/02/codeforces.html

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