Для облегчения тестирования решения интерактивных задач сделал С++ шаблон.

Состоит из следующих основных частей (см. код):

1) OnlineJudgeInteractor: отвечает на вопросы через stdin/stdout
2) LocalTestInteractor: в конструкторе принимает секретную информацию и отвечает на вопросы, зная её
3) Solver: принимает на вход любой IInteractor, задаёт вопросы, возвращает найденный ответ

Codeforces Round #272 (Div. 1) and Codeforces Round #272 (Div. 2) round statistics

Codeforces Round #270 round statistics

Codeforces Round #269 (Div. 2) round statistics

Codeforces Round #268 (Div. 1) and Codeforces Round #268 (Div. 2) round statistics

Codeforces Round #265 (Div. 1) and Codeforces Round #265 (Div. 2) round statistics

Brief stats for rounds
Codeforces Round #262 (Div. 2)
Codeforces Round #263 (Div. 1)
Codeforces Round #263 (Div. 2)
Codeforces Round #264 (Div. 2)

Codeforces Round #261 (Div. 2) round statistics

Codeforces Round #260 (Div. 1) and Codeforces Round #260 (Div. 2) round statistics

Codeforces Round #259 (Div. 1) and Codeforces Round #259 (Div. 2) round statistics

MemSQL Start[c]UP 2.0 - Round 1 round statistics

Codeforces Round #258 (Div. 2) round statistics

Codeforces Round #256 (Div. 2), Codeforces Round #257 (Div. 1) and Codeforces Round #257 (Div. 2) brief round statistics

Codeforces Round #FF (Div. 1) and Codeforces Round #FF (Div. 2) round statistics

Codeforces Round #254 (Div. 1) and Codeforces Round #254 (Div. 2) round statistics

Codeforces Round #253 (Div. 1) and Codeforces Round #253 (Div. 2) round statistics

Zepto Code Rush 2014 round statistics

Codeforces Round #252 (Div. 2) & Codeforces Round #251 (Div. 2) round statistics

Codeforces Round #250 (Div. 1) and Codeforces Round #250 (Div. 2) round statistics

Codeforces Round #249 (Div. 2) round statistics

В настоящее время идет Марафон-раунд. Задача RectanglesAndHoles, на мой взгляд, интересная.

Правилами запрещены любые обсуждения, в т.ч. переводы и формулировки условия, до конца раунда, кроме официального форума.

Регистрироваться и посылать решения можно до 4 июня 2014 21:00 MSK.
После раунда предлагаю обсудить решения.

Codeforces Round #248 (Div. 1) and Codeforces Round #248 (Div. 2) round statistics

Codeforces Round #247 (Div. 2) round statistics

Codeforces Round #246 (Div. 2) round statistics

There were two reasons, prompted me to begin round statistics acquiring:
1) it was interesting to know failed solution percentage
2) it was interesting to study javascript + DOM + Chrome Extension and develop something using it

It was a new tool for me, and after samples & forums reading, the First Post was created.
After the first three hours, it's score was -7. Am I the only one, who is interested to know failed solution percentage?
24 hours later, I got the answer for the question: no, not the only one ( +123 ).

Thanks to your support, comments and suggestions, the statistics progressed from round to round.
My Javascript-skill was increased from "Below Hello World!" to "Above Hello World!". Your upvotes maked me develop new features and fix spotted bugs.
Even after First Post with Graphs was estimated positively, I could not even imagine about getting to the Top-10 Contributed.

Several days ago, the Contribution has reached the Top-1

It was impossible for me to keep this fact without comments. To be precise:

I must say thanks to everyone, who upvoted my statistics posts, who made any suggestions or asked questions.
Thanks a lot! I really appreciate your support!

Some stats about stats scripts:
JS files count: 19
JS lines of code: 5561.

Bonus:
Screencast (10:36) of Codeforces Round Statistics creation process.

What's next?
- Make the deprecated FAQ actual
- let's wait and see ;)

P.S.

Donate via PayPal
Here could be a donation link.
But my PayPal account was blocked after my attempt to "support myself".
Maybe, later :)