By KADR, 8 years ago, translation, ,
Hello everyone!

Codeforces Beta Round #97 will take place on Friday, December 9th at 19:00 MSK. This will be my second classical Codeforces round and I hope it won't be the last one :)

I'd like to thank maksay, Shtrix, it4.kp, RAD and Delinur for their help in preparing contest, testing problems and translating them into English.

Good luck!

UPD: Due to technical reasons the round start time is shifted 5 minutes forward.

UPD 2: Due to the large number of participants and large number of tests the testing will finish not soon.

UPD 3: The testing is over. Thanks for participation! I apologize for a very long testing process.

The winners:
Div 1
4. Shef
7. ania
9. NALP

Div 2

UPD 4: The editorial is released.

• +237

 8 years ago, # |   0 Thanks for your hardwork.By the way, anyone can explain me what is "classical Codeforces round" means?
•  8 years ago, # ^ |   +32 I can guess that it's a typical Beta round, as opposed to Unknown Language Round or other unrated events with different rules.
 8 years ago, # |   0 thanks for your hard work,I'd like to take it.
 8 years ago, # |   0 Apparently, I accidentally registered twice...
 8 years ago, # |   +10 В связи с изменением формата страниц Codeforces прошу обновить CHelper до последней версии---Due to format of Codeforces pages change please update CHelper to the latest version
 8 years ago, # |   +7 funny, I could challenge one solution with Anti QuickSort, be carefull next time!
•  8 years ago, # ^ |   +5 AntiQuicksort detected in final tests
•  8 years ago, # ^ |   +10 There were a few successful hacks made with antiquicksort and they were added to the final testset.
•  8 years ago, # ^ |   0 Are all successful hacks added to final tests?
•  8 years ago, # ^ |   0 Well, I'm not sure about all of them, but most of them are added to the final testset.
•  8 years ago, # ^ | ← Rev. 2 →   +5 I forgot that I have antiquicksort generator :(FFFFFFFFFFUUUUUUUUUUUU, I also have anti-java-sort generator :(
•  8 years ago, # ^ |   0 in last comments someone wrote: "some of challenges are added to system tests"
•  8 years ago, # ^ |   0 Does this mean we shouldn't use quicksort in sports programming?  Is qsort(3) or std::sort safe?
•  8 years ago, # ^ | ← Rev. 2 →   +9 I believe C++ STL sort uses introsort so that is safe.EDIT: I should say, rather, that GNU C++ does this. The actual standard does not require it.
•  8 years ago, # ^ | ← Rev. 2 →   +5 quick sort has random parts, hasn't? so what the hell is Anti Quicksort? :D
•  8 years ago, # ^ |   0 In practice a lot of quick sorts are implemented by taking the median of the first, last and middle element instead of using random. This has been shown to give great performance in practice.
 8 years ago, # |   +11 I hope that today system testing will be fast...
•  8 years ago, # ^ |   0 It seems that it's not as usual! :(
 8 years ago, # |   +5 Great contest! Questions was so interesting! Thanks Codeforces that cause me to advance a lot in algorithms!
 8 years ago, # |   0 I am baffled, and I tried for ages to figure out why my B.cpp kept failing the very first pretest. http://pastebin.com/Jpa6M6DXThings like the paralel and area check I added after trying many things. Initially I only had distance and perpendicular checks. I noted that Romka passed system tests using only distance and perpendicular checks, and his method to check if there is a right angle is equivalent to mine. So, really any help is appreciated.
•  8 years ago, # ^ |   -14 "Romka passed system tests"Do you see the system tests finished? I see "Pending system tests". Codeforces system testing uses to start early is it something happening now that doesn't make possible to start system testing?
•  8 years ago, # ^ | ← Rev. 2 →   0 I meant pretests, my problem is that I can't pass even pretest #1
•  8 years ago, # ^ |   +3 Also, isn't it usual for pretest#1 to be the example case? If that is the case then this is very strange because the examples work correctly in my machine. If that's not necessarily the case, that's good to know.
•  8 years ago, # ^ |   +3 Pretest #1 is always the first example case.
•  8 years ago, # ^ |   0 Thanks. Though I am now officially confused.Maybe it is something about compiler versions being different.
•  8 years ago, # ^ |   0 Maybe garbage in variables?
•  8 years ago, # ^ | ← Rev. 4 →   0 I run your program in my machineFirst caseyour outputYES 1 2 3 4 5 6 7 8but it have to beYES5 6 7 81 2 3 4
•  8 years ago, # ^ |   0 I get the correct result in my computer. I will try getting identical compiler setup to CF.
•  8 years ago, # ^ |   0 I have been using gcc 4.2 to compile and test locally. If I change it to 4.3 , I start getting WA in the first case. CF uses 4.6 , so there's probably a change in 4.3 that stayed.I guess it would have been better to figure out that pretest#1 was the first example, that way I would have focused on compiler-related things.
•  8 years ago, # ^ | ← Rev. 2 →   0 Edit: No, wrong theory.
•  8 years ago, # ^ |   +4 I just forgot a "return false" in isRectangle(), this caused undefined behavior, so it behaves differently in different compiler versions.
•  8 years ago, # ^ | ← Rev. 3 →   0 ignore
•  8 years ago, # ^ |   +4 he first make while( cin >> x[0] >> y[0] ) then read other data in loop 1->8
 8 years ago, # | ← Rev. 2 →   +3 div1.C, when the digits on the cards got blurred, do the players know thedigits? How do they make their decisions?
•  8 years ago, # ^ |   0 Yes, they know the digits. One need to find the outcomes for all possible replacements of '?' with '0' and '1'.
 8 years ago, # |   +5 Very nice problem set, thank you for this competition! :)
 8 years ago, # |   0 Tottally off-topic but I don't know where to ask. What is the contribution in CodeForces?
•  8 years ago, # ^ |   0 It's something you gain/lose writing your comments/blog:)
•  8 years ago, # ^ |   0 http://codeforces.ru/help#q99 paragraph
 8 years ago, # |   0 We have been waiting 1 hour for less than 20% done of the system test! :(
 8 years ago, # |   +3 one of the finest set in code forces.......thanks to KADR......... :)
 8 years ago, # |   +1 As the codes are tested in the same order they are submitted, don't you think it may be a good idea to show the time when the last tested code was submited during the system tests?
•  8 years ago, # ^ |   +17 You can open the "Status" tab and watch it there.
 8 years ago, # |   +8 Was this was really necessary to make 100+ test cases? If you only keep tricky cases then may be 50> case could be enough for testing and will take smaller system testing time :-|
•  8 years ago, # ^ |   +10 Most of the successful hacks were also added to the final testset.
•  8 years ago, # ^ |   +34 For the next time it may be a good idea to make the tricky test cases be the first one so there's no need to test 200 cases before test case 201 fails.
 8 years ago, # |   +15 It would have been better to include the cycle1111in Div1-D sample tests.Many didn't pass the pretests because of this.
 8 years ago, # |   +6 I just saw the solution to Problem B Div 2, Lolz, my solution to the problem is so crappy !! I can't believe it didn't strike me. Well, you always learn something new here. :)
 8 years ago, # |   +18 too slow system test :(
•  8 years ago, # ^ |   +11 Check system's verdict is Time Limit :)
 8 years ago, # |   +3 Now around 2 hours waiting and only less than 50% done of the system test! :\
 8 years ago, # |   +8 f5 after f5, tired :(
•  8 years ago, # ^ |   +15 f5 will be broken tonight...
•  8 years ago, # ^ |   0 surely :)
•  8 years ago, # ^ |   +16 I'm not sure if the system testing is done on the same server, but if that is the case, ironically, pressing f5 will only make it slower ;)
•  8 years ago, # ^ |   0 Count them so you don't get bored :D
•  8 years ago, # ^ |   +9 :( I lost my count somewhere after 999997
•  8 years ago, # ^ |   +6 And the waiting world record goes to the guy who submitted last.
 8 years ago, # |   0 At last! :)
 8 years ago, # |   +1 Great contest, I really enjoy, thanks to all whose work makes it possible  that this site is.
 8 years ago, # |   0 I think Petya is the person who enjoyed the contest most. He received a lot of gifts from his mother in this end of year! Wondering if it could happen to us...Seriously now, the system test case took really a long time, but ignoring this fact, I liked the contest. I think the problems difficulty were indeed propotional to the problems' points/values, and the statements were easy to read.
 8 years ago, # |   0 Great contest!By the way, anyone can give me some ideas to solve problem E-div2?
 8 years ago, # |   +2 the meaning of problem A is ambiguous.
 8 years ago, # | ← Rev. 6 →   0 really enjoyed the contest, thnx . wish I didn't make a stupid mistake in D :(
•  8 years ago, # ^ |   +1 really enjoyed the contest, thnx KADR. wish I didn't make a stupid mistake in D :(example =)read this.
•  8 years ago, # ^ |   0 thnx, I got it now.
 8 years ago, # |   0 I failed in case 222 in problem 'Rectangle and Square' and I can't find what the problem is in my code, did anyone encountered the same problem? May anyone help?
•  8 years ago, # ^ |   +1 0 0 1 0 2 0 1 2This isn't a valid rectangle.Input:0 0 1 0 2 0 1 2 50 50 50 51 51 51 51 50Output:NO
•  8 years ago, # ^ | ← Rev. 2 →   +1 Check the part of your code where you check whether it is a rectangle or not.
•  8 years ago, # ^ |   0 Oh you are right :) .. I didn't think of such a case.Thanks.
 8 years ago, # |   0 What is Test#7 in Problem D in Div1 (Cycle)?
•  8 years ago, # ^ |   0 Go to your submissions and left click on the number of your submissions and scroll to the bottom. In your case you need submission 951386. Test: #7, time: 10 ms., memory: 37576 KB, exit code: 0, checker exit code: 1, verdict: WRONG_ANSWER Input 4 5 11111 10101 10001 11111  Output 15  Answer 0  Checker Log wrong answer 1st numbers differ - expected: '0', found: '15' 
•  8 years ago, # ^ |   0 Thank you
•  8 years ago, # ^ |   0 No problem. :)
•  8 years ago, # ^ |   0 If the test cases is too large, is there any way to download them?
•  8 years ago, # ^ |   0 I don't think so.
 8 years ago, # |   +15 when will the editorial for the contest be available ?
•  8 years ago, # ^ |   0 Russian version of the editorial is already published. I'll translate it today or tomorrow.