The Open Competition is an annual week-long competition for Estonian high school students which serves as the first contest of the season. This year, we are welcoming international participants as well. The contest started on 15 October, 10:00 EEST and lasts a week, ending at 22 October, 00:00 EEST.

The contest consists of 7 problems with scoring distribution 20-30-40-50-60-60-60. The problems will have partial scoring. The first five problems are "classical" problems of increasing difficulty, while the last two slots are reserved for output-only, interactive, out of scope, approximation, optimization — just in general "weird" problems. The problemset should be interesting for most Div. 2 participants.

Problem statements will be available in Estonian, English and Russian. However, to register, you will need to navigate through a bit of Estonian.

• Summary of the rules in English
• Registration (Google Translate works well; foreign participants should sign up in the "other" category and enter the country name in the "school/institution" field)
• Ranking
• The contest itself

Please note that you might not appear on the scoreboard immediately after registering.

#define rep(i, l, r) for ((i) = (l); (i) < (r); (i)++)

Things like that are pretty common. Why do so many of you need to do things like this? What is wrong with a good old for-loop? Is it that slow to write one explicitly?

I tried to add a problem prepared in Polygon to a mashup contest. Instead of the problem however, the statement shows this wonderful piece of art:

What is going on?

To my (untrained) eye, it seems that Codeforces servers are unable to handle the traffic that comes with a regular Codeforces round. If this is indeed so, a possible solution to alleviate the server load would be to simply limit the number of participants in any given contest: only allowing a fixed number of people to register for the contest — first come, first serve. A limited-access contest is better than "no" contest at all.

Should Codeforces do this? Discuss.

(of course if the issues originate elsewhere then don't mind this)

Title says it all. What are some of your favourite problems in competitive programming?

I was hoping to see discussion on the problems, but the announcement seems to have disappeared.

EDIT: Back up!

I often, not that often, but still often see things like this while hacking:

#define MIN(a,b) (a) < (b) ? (a) : (b)
#define MAX(a,b) (a) > (b) ? (a) : (b)
#define ABS(a) (a) > 0 ? (a) : -(a)

While these are not as common as other (dubious) preprocessor macros, I still see these being used fairly commonly. There are, in my opinion, several downsides to using these -- if the inputs were functions, one of them gets executed twice.

So I want to ask, is there any advantage to using these over std::min(a, b) and others?