Hey, I wanted to start new series about hacking. I think that this part of programming contests is really underrated, but can be helpful for both people solving problems (you should know what tricky cases you need to consider) and people writing problems (you should know how to write nice tests covering everything).

So in this series, which I will try to continue, I will talk over hacks at Codeforces Rounds. I will try to do some statistics and take a look at most common mistakes in passing contests.

It is my first article related to hacking (and first at all :)), so feel free to suggest something, correct me on some errors or mistakes (my English still can be much better :)) and tell about your hacks. Thanks in advance!

So let's move to Codeforces Round 262 (Div. 2).

Update: added country wise statistics (at the end).

Update: added chart with hacks over time and first hacks.

Update: the handles are now full of colours, with many thanks to awesome accidentallygivenfuck!

Update: added section "biggest gap" (between rating of the hacker and defender).