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### fcspartakm's blog

By fcspartakm, history, 2 years ago, translation, ,

Hello, Codeforces!

Educational Codeforces Round 15 will take place on 29 July 2016 at 18:00 MSK for the first and the second divisions.

The round will be unrated for all users and it will be held with extented ACM ICPC rules. You will have two hours to solve six problems. After that you will have one day to hack any solution you want. You will have access to copy any solution and test it locally.

We with Mike MikeMirzayanov Mirzayanov decided to prepare this Round, because Edvard Edvard Davtyan is very busy at his new job. Good luck and have fun!

UPD Competition completed! Thank you all! Editorial

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 » 2 years ago, # |   0 Auto comment: topic has been translated by fcspartakm (original revision, translated revision, compare)
 » 2 years ago, # |   -30 This is unrated for all user meant?
•  » » 2 years ago, # ^ |   +8 Of course.
 » 2 years ago, # |   -41 Where is Edvard ?
•  » » 2 years ago, # ^ |   +29 "because Edvard Edvard Davtyan is very busy at his new job"
•  » » 2 years ago, # ^ |   +15 In the mountains.
 » 2 years ago, # |   -70 有人吗？？
•  » » 2 years ago, # ^ |   -66 我是ljd
•  » » » 2 years ago, # ^ |   -35 you are Loser Junk Dick(LJD)
 » 2 years ago, # | ← Rev. 2 →   -37 CF contest no 702. If we truncate trailing even digits, we would get lucky 7!Hope everyone get points multiple of 702!(Do not see rev 1, it was a mistake!)
•  » » 2 years ago, # ^ |   +35 It is number 702.
•  » » » 2 years ago, # ^ |   +18 Ow! You are seeing too old version, see the updated revision!
 » 2 years ago, # |   -14 hello
•  » » 2 years ago, # ^ |   +1 hi! its time to start the contest. So, do not waste time now!
 » 2 years ago, # |   -14 in B in the first example shouldn't the pairs of indices included in answer be: (1, 4) and (2, 4) instead of (1, 4) and (3, 4)?
•  » » 2 years ago, # ^ |   -16 No,it shouldn't :D
 » 2 years ago, # |   +6 Will we be able to see the tests before hacking period ends?
•  » » 2 years ago, # ^ |   +6 YSE
 » 2 years ago, # |   +20 Well, i found out that my first submission is incorrect, so i resubmited but its still showing the first submission
•  » » 2 years ago, # ^ |   +1 and it shows hack it for both submission too .. i wonder what happen if someone got successful hack on the old one
 » 2 years ago, # |   0 Has anyone tried solving D using a binary search?
•  » » 2 years ago, # ^ |   0 Ive tried with ternary search, but WA on test 22 :(
•  » » 2 years ago, # ^ |   +1 Solution with ternary search
 » 2 years ago, # | ← Rev. 2 →   0 How is it my solution for D with map runs in 200 ms but solution with multiset gets TLE (>3000 ms)?multiset: 19483894map: 19499476Is multiset really so slow? Why?
•  » » 2 years ago, # ^ | ← Rev. 2 →   +46 complexity of multiset.count(value)` is not O(log(N)) but O(log(N) + Count).
•  » » » 2 years ago, # ^ |   0 Oh. Thanks.
 » 2 years ago, # |   -26 I downvoted every single comments:D
•  » » 2 years ago, # ^ |   -26 I will be back
•  » » 2 years ago, # ^ |   +18 But you cannot vote for your comments.
•  » » » 2 years ago, # ^ |   0 no, I can use a fake account to do that. That's why I said I will be back:D
•  » » 2 years ago, # ^ |   +6 nice life you have there m8
 » 2 years ago, # |   0 Got "unexpected verdict" in hack 245453, 245473 and 245477.
•  » » 2 years ago, # ^ |   0 And 245205 too.
•  » » » 2 years ago, # ^ |   0 Fixed.
•  » » » » 2 years ago, # ^ |   0 thank you
 » 2 years ago, # |   +5 How to solve problem C if all the points were on 2 dimensional plane? With k-d trees a straightforward is possible, is there another/better solution?
•  » » 2 years ago, # ^ | ← Rev. 2 →   0 Hmm. Deleted.
 » 2 years ago, # | ← Rev. 2 →   +3 Hi, In this this round, I've tried to hack the others code in hacking phase; but I couldn't find any buggy code or some tricky test case to hack and I've finished with an unsuccessful hacking attempt! After this try, I noticed that I should have a suitable mechanism for hacking. So what's your idea about it? what's your suggestion for me to do better in hacking phase? And here my questions about hacking: How should I choose someone to hack? Randomly from common standing or needs some logical decision? When's the right time to hack in normal rounds? What's the right procedure to hack? Read codes and then break it with a test case or just check every code with some already prepared tricky test cases? How should I make test cases? According to someone code, generate randomly or make by hand after thinking about the problem?
•  » » 2 years ago, # ^ |   0 I would also like if someone replies on this.
•  » » » 2 years ago, # ^ | ← Rev. 3 →   0 This is a good question! I've faced to this event and It's my question too. So I'm waiting for the answer...