Petr's blog

Live interview — postponed
By Petr, 12 years 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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Facebook Hacker Cup results
By Petr, 12 years 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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TCO 2011 Finals
By Petr, 13 years ago, translation, In English

Preview: http://petr-mitrichev.blogspot.com/2011/09/topcoder-open-2011.html

Live coverage in 3 hours at: http://petr-mitrichev.blogspot.com/

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ACM ICPC 2011 World Finals
By Petr, 13 years 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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Codeforces Beta Round 50 impressions
By Petr, 13 years ago, In English
http://petr-mitrichev.blogspot.com/2011/01/codeforces-beta-round-50-how-to-avoid.html

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Kill backtracking!
By Petr, 14 years 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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Beta 2
By Petr, 14 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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