Today is the second round of the Open Moscow Programming Championship By CROC will be. Start is planned at 19:00.
Competition will happen by usual rules of Codeforces, with hacks and score falling in process of time. All contestants who passed score no less than contectant of the 300-th place in the Round 1, can participate in the Round 2. Every other contestants can patricipate the Round 2 out of competition. Specially for contestants of the second division we prepared more easy unofficial problemset. The official problemset and the unnoficial one have some common tasks.
Round will be rated for all participants.
Some number of problems are waiting you. They are roughly ordered by the increasing complexity. Score distribution is standard for both divisions (500-1000-1500-2000-2500). Don't forget that during contest your solutions will be tested on a small set of pretests. Testing on full testset will be after end of the round. Pretests can don't cover all cases of input data, so you should test your solutions very carefully.
It is strictly forbidden to publish statements/solutions of the problems before round will be end. Also you shouldn't to talk about problems, discuss some things about possible solutions of them. Let's be honest! You can discuss problems after the end of round.
Top 50 contestant will be allowed to the Final Round. Also all contestant with score not less than score of the 50-th contestant will be passed.
The round was prepared by Ripatti, havaliza, Gerald, RAD, MikeMirzayanov, Delinur.
Good luck for all!
UPD. We remind that the final of the Open Championship of Moscow and Moscow Region Programming (CROC) take place on April 27 in the office of the CROC. Note that CROC does not pay for the road and residence of the finalists. All participants must arrive at the final in the office of the CROC (Moscow) in the morning on April 27.
After the competition all participants will be provided to fill the form on the ability to participate in the finals of the competition. The first 50 participants on the results of the competition, which will confirm their participation in the finals, will be invited to final competition. You can confirm participation in the finals during the day after the end of Round 2.
It is recommended to fill the form, regardless of your results in Round 2, as large number of participants can reject the participation in the final.
Does anybody thinks that solution for problem C is too nice? :)
P.S. (To not misunderstand) I don't find that solution with 2-3 if/else statements is a nice one
It's up to your own point. Personally, I found it interesting to simulate the game on Microsoft Excel ( sounds weird :) ). Some problems might cost you more time to work without computers, for instance, you can check problem D from last year Google Code Jam qualification round.
P/s: 1590260 is certainly not a solution with 2-3 if/else :)
At least it was solvable by few if/else statements and possibly without full understanding of its rightness.
Is there a way to check which test cases failed?
go to your submissions and click to submission id
I seem to see that submissions by a few people are hacked. However they got accepted in the end because they passed system test?
For example: problem C by WJMZBMR, kuniavski and Dmitry_Egorov.
May I know why this is the case?
These solutions were resubmitted after being hacked and got OK
If you are hacked, you can (and should ;) ) resubmit the solution. It is then tested on the pretests and also on the hack case. However, if you had locked the problem and then got hacked, you can no longer resubmit. (But you can still hack others.)
Who can I ask for visa letter to go Russia?
I think u should write a letter to some officials (probably Mike Mirzayanov), but I suppose it's quite impossible to receive a visa in such a short time.
Please explain the logic for solving problem D(HYPER STRING).
Can somebody point to editorial for this round ?
Problem analysis usually appears in one-two days after the contest, don't be so impatient =)
Where can I find the analysis in English
In Problem C. Why does the second win when the input is “5 5 1 1 5 4”
That was the most important hack case, I think ;) The distance between the pawns is (abs(x1-x2),abs(y1-y2)) = (4,3). If the first player moves so that the distance between the two pawns becomes (4,2), then second wins quite easily. It seems better for the first player to reduce the distance to (3,3). So we have
and now Second moves. The trick is that he should glue this cell:
Then, if the first moves to
the Second should counter with
From here, he can block whatever first responds with. If instead First were to move to:
then Second blocks the upper pawn with
and when first moves to
then second "finishes" with
and the rest is easy.
Thank you very much!
Sorry for bringing this up again, but how to contact with the contest organizers? Only five days remaining and there's no information for non-Russian coders about how to travel to Russia.
Try contacting with MikeMirzayanov
I've sent email.