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### ivan.popelyshev's blog

By ivan.popelyshev, 9 years ago, ,
We need the new thread specially for the final.

21:00 MSK (less than in a hour).

scoreboard

• +35

By ivan.popelyshev, 9 years ago, translation, ,
SRM 498 will be held at 26 february 17:00 GMT. Good luck, have fun!
And may The Force be with you.

• +33

By ivan.popelyshev, 9 years ago, translation, ,
Discuss SRM 490 there.

• +7

By ivan.popelyshev, 10 years ago, translation, ,
I am working as a teacher in Lyceum Fryazino.

I decided to teach my computer science group to code Java programs. As a learning IDE i chose Greenfoot.

Jedi tetris.

My score is 9100.

P.S.
Thanks to "Export" button i uploaded my scenario to the web-site as a java applet.

• +3

By ivan.popelyshev, 10 years ago, translation, ,

### Intro

Every high school or college coach quickly comes to mind about his own online judge system. We can deal with huge systems like  e-judge or pcmc-2, we can make something our own like contester or acmp, but in any case to create a contest we should

• +12

By ivan.popelyshev, 10 years ago, translation, ,
Lets start from the end.

## Problem С. Commentator problem

Let R be the distance from point А to a circle with center О and radius r. From this point the circle is observed at the angle .
So, the three stadiums are observed at the same angle if R1 / r1 = R2 / r2 = R3 / r3.
Take two different points A, B. The set of points C that AC / BC = const is either a line (perpendicular bisector of AB) or a circle with center somewhere on the line AB. This circle is easy to find. It contains two points that lie on AB and satisfy AC / BC condition.