### Nickolas's blog

By Nickolas, 4 years ago, translation, ,

The contest is over; I hope you've enjoyed it :-) Editorial is here. See you next year!

The fourth April Fools Day Contest will take place on Friday April 1st. This is a joke competition in which solving the problem is often easier than figuring out what the actual task is. Thanks to kit1980 and Codeforces team for their help in preparing problems.

In this round you'll be given 7 weird problems and 2 hours to solve them. The contest will use ACM ICPC rules (no hacks, the standings are decided by the number of solved problems and penalty time earned on them), and it will be unrated. You can submit solutions in any language allowed by Codeforces — well, unless the problem says otherwise ;-) To get an idea of what the contest will look like, you can check out the contests of the past years: 2012, 2013, 2014.

Be warned, to enjoy competing in this round you'll need a sense of humor compatible with mine! Good luck, and have fun!

• +605

 » 4 years ago, # |   +146 April Fool's joke:Us: Woo, unrated contest.CodeForces: April Fool's, it's rated.Us: rating dropsCodeForces: Just kidding... all newbies become legendary grandmaster...
•  » » 4 years ago, # ^ |   +29 Yeah, lets invert the ratings for one day. Like, for exampple, your rating tomorrow=Tourist's rating-your actual rating. Fun!
•  » » 4 years ago, # ^ |   -34 So,It's rated or not?
•  » » » 4 years ago, # ^ |   0 It is mentioned that it isn't rated. But I don't actually believe :)
 » 4 years ago, # |   -17 Awesome!
•  » » 4 years ago, # ^ |   +14 Yes the joker man!!! You did the best!
 » 4 years ago, # |   0  You can submit solutions in any language allowed by Codeforces — well, unless the problem says otherwise...oops, fells like I should have learned another language rather than just c++, but wait a second, it's April Fools day, so probably a joke ^_^
•  » » 4 years ago, # ^ |   0 Check this problem B. Mysterious Language from April Fools Day Contest 2014 .
 » 4 years ago, # |   +5 Can we participate as a team ? It would be more fun I think.
 » 4 years ago, # |   -16 Is it ok to privately collabrate with friends during contest?
•  » » 4 years ago, # ^ |   +34 You mean privately cheat?
•  » » » 4 years ago, # ^ |   -16 Well it's April Fools......
•  » » » » 4 years ago, # ^ |   +87 you want to distribute the fun between you and your friends while you can have it all for yourself?
•  » » » » » 4 years ago, # ^ |   0 Sharing is Caring.
 » 4 years ago, # |   +22 The problem statements for the previous April Fool's contests are insane! It will be fun! Eagerly waiting for it! But please don't April Fool us.Hope it's really unrated!
•  » » 4 years ago, # ^ |   +19 That would be the evilest thing I could imagine
 » 4 years ago, # |   +11 I am not participating. What if the part that says that the contest is unrated is an April fools prank and it is actually rated?
•  » » 4 years ago, # ^ |   +42 What if there's actually no contest and the announcement was just a prank?
•  » » » 4 years ago, # ^ |   +16 What if the complete announcement is true and the part that is fooling us is the part about April Fool, while actually they are not making any fool out of us?
•  » » » 4 years ago, # ^ |   +14 That would be so last year. I'm not really into that kind of jokes, I prefer something more elaborate ;-)
•  » » » » 4 years ago, # ^ |   0 I value your honor among thieves attitude.
 » 4 years ago, # |   0 Seems interesting! I don't mind if "unrated" is a joke, it makes it a lot more exciting in my personal opinion.Well, have fun everyone. ;-)
 » 4 years ago, # | ← Rev. 2 →   -12 Is it rated?
•  » » 4 years ago, # ^ | ← Rev. 2 →   +6 The author says unrated but the comments say otherwiseIt's not an easy question :D
•  » » » 4 years ago, # ^ |   +9 You don't get it. He's doing an experiment.
•  » » 4 years ago, # ^ |   +3 The contest will use ACM ICPC rules (no hacks, the standings are decided by the number of solved problems and penalty time earned on them), and it will be unrated.
•  » » » 4 years ago, # ^ |   -11 Is it rated?
•  » » 4 years ago, # ^ |   +3 why not))
 » 4 years ago, # |   0 Think too much but so funny！
 » 4 years ago, # | ← Rev. 3 →   +4 There may be an April Fool Problem. The Problem is Present but no Problem Statement , Input & Output . Like This :
 » 4 years ago, # |   0 From blog/entry/4255: A special contest written by me and no special programming language? Impossible!
 » 4 years ago, # |   0 It's my personal contest, 10x 2 Nickolas :)
 » 4 years ago, # |   +11 waited for two years...
 » 4 years ago, # |   -18 hope it's rated ~ so I can become a specialist
 » 4 years ago, # |   +3 This is what had happened in 2014th April Fool Contest. Really making us Fool :-p
•  » » 4 years ago, # ^ |   +18 I read some of its problems and understood none of them :/ is it normal?
•  » » » 4 years ago, # ^ |   +8 It's expected.
 » 4 years ago, # | ← Rev. 2 →   -7 There is no contest, It's a Joke :D
 » 4 years ago, # |   -6 Sounds interesting..
 » 4 years ago, # |   +1 That is exactly at 0:00 on April 2 in Beijing ,which is mocking!
•  » » 4 years ago, # ^ |   0 Same here.
 » 4 years ago, # |   0 Hey, guys! I didn't have a Codeforces account until last year's October and now that I see that there were April Fools Day Contests, can anyone tell me why hasn't there been a contest last year?
•  » » 4 years ago, # ^ |   +1 Something didn't end up very funny last year. They've been fooled.
•  » » 4 years ago, # ^ |   0 Nickolas was busy
•  » » 4 years ago, # ^ |   0 The whole contest was a prank.
 » 4 years ago, # |   +15 It's 13-be-dar in Iran, we are supposed to go outdoor for a whole day and spend the day with family and nature. Well, except programmers, it seems!
•  » » 4 years ago, # ^ |   0 Actually it seems Iranians welcomed this contest a lot!
 » 4 years ago, # |   +5 what is the solution of A problem
•  » » 4 years ago, # ^ |   +17 Editorial will be published in 1 hour :-)
•  » » » 4 years ago, # ^ |   +46 but i need now
•  » » » » 4 years ago, # ^ |   0 Search oeis.org for Da Vinci and you'll find a fake powers of 2 sequence. Copy that and AC.
•  » » » » » 4 years ago, # ^ |   +3 The interesting thing is when I searched "da vinci" on OEIS, only fibonacci thing came up. Now it shows the other one. Maybe I didn't wait enough for all search results to come :/
•  » » » » » 4 years ago, # ^ |   0 How did you find this webpage?
•  » » » » » 4 years ago, # ^ |   +6 And I searched it on Google :'(
•  » » 4 years ago, # ^ |   +2 why?
•  » » 4 years ago, # ^ |   +3 lol
•  » » 4 years ago, # ^ |   0 utkununfakesi this is fake account.Don't care this guy.
•  » » 4 years ago, # ^ |   +3 http://oeis.org/A221180searched by keyword "Da Vinci"...
 » 4 years ago, # |   +12 It was awesome!!! (the best joke I can say :D )
 » 4 years ago, # | ← Rev. 2 →   -35 。
•  » » 4 years ago, # ^ |   0 Bad room mate :(
•  » » 4 years ago, # ^ |   +3 Bro, Can't you wait until the contest ends?
•  » » 4 years ago, # ^ |   -6 ....
 » 4 years ago, # |   +29
 » 4 years ago, # |   0 Wow amazing tasks. Waiting for the ultimate prank "the contest is rated" to return to yellow. :P
 » 4 years ago, # | ← Rev. 2 →   +5 So what's the deal with problem F? Is it really OEIS? Is there a way to do it without URL requests?
•  » » 4 years ago, # ^ |   +8 How to compress ~280000 integers to 64KB? Codeforces doesn't accept my solution :(
•  » » » 4 years ago, # ^ |   +30 How did you download them in the first place?
•  » » » » 4 years ago, # ^ |   +19
•  » » 4 years ago, # ^ |   0 1 + sum of all digits, and '0' == '9'
•  » » 4 years ago, # ^ |   +1 It's blackjack sum. OEIS is a prank.
•  » » 4 years ago, # ^ |   0 They are just poker card numbers! A = 1 10 = 10
•  » » 4 years ago, # ^ |   0 https://oeis.org/A221033this is the only thing about the first sample that I found and don't understand it :(
•  » » 4 years ago, # ^ |   +4 It's blackjack
 » 4 years ago, # |   +3 Problem G. I see what you did there :)
 » 4 years ago, # |   +5 The problem is a joke haha
 » 4 years ago, # |   0 Hey, what's wrong with submission for G using Python? Support of this language is discontinued, starting today. Please rewrite your project using something more modern.
•  » » 4 years ago, # ^ | ← Rev. 2 →   +3 You should submit it in 2 languages and add a "kitten" at last
•  » » » 4 years ago, # ^ | ← Rev. 2 →   0 Hmm... Thought about the second language, but what is a #kattie? And how do you know that?
•  » » » » 4 years ago, # ^ |   +3 The judger will notice you add a kitten when you submit with the second language
•  » » » » » 4 years ago, # ^ |   0 Wow, that awesome, thank you
•  » » » » 4 years ago, # ^ |   +3 When you submit it with 2nd language, you will get something like: So many characters... Can't your code be shorter? Please remove 8 more characters.'Then when your code is short enough, you will get: Needs a finishing touch... Can you add a kitten?And you need to add a 'kitten' in your program, for me it means you need to make it shorter again..
•  » » » » » 4 years ago, # ^ |   +5 Aha, now I got the title :)
•  » » » » » 4 years ago, # ^ |   -8 I copied someone else's code, and got So many characters... Can't your code be shorter? Please remove 117 more characters dafuq!
 » 4 years ago, # |   0 I really need to know how to solve problem A. It's driving me crazy
•  » » 4 years ago, # ^ |   0 I got the solution from here
•  » » » 4 years ago, # ^ |   0 What is that? It's not 2^n?
 » 4 years ago, # |   0 really don't understand why problem A like this...
 » 4 years ago, # |   0 How do I solve D? I kind of saw a pattern of a cipher but couldnt decode it
•  » » 4 years ago, # ^ | ← Rev. 4 →   0 number of '1' in octal form of input (sry for bad English)
•  » » 4 years ago, # ^ | ← Rev. 2 →   +3 plain Brainfuck (You SHOULD recognize it.) Malbolge (Search "zyxwvutsrqponmlkjihgfedcba esolang" on Google) Piet (Search "C00000 esolang" on Google) Befunge (You MIGHT recognize it. If you don't, check the list of esolangs with >
•  » » » 4 years ago, # ^ |   0 Some years ago here was a contest with Befunge as the only (?) acceptable language. That was awesome.
 » 4 years ago, # |   +3 Can we still submit the solution after the contest ?
 » 4 years ago, # |   +50 Loved F. Epic troll.
 » 4 years ago, # |   +5 For G, why WA on test 1 when all verdicts are OK?
•  » » 4 years ago, # ^ |   0 this question is driving me crazy. I saw my code to pass all test and get WA on 1 twice. Still hoping for some kind of magic
•  » » » 4 years ago, # ^ |   +5 Hint: click on the "Wrong answer on test 1"
•  » » » » 4 years ago, # ^ |   0 We had to use different languages? Can you tell me about any of them?
•  » » » » » 4 years ago, # ^ |   0 Yes, the problem should be solved using two languages. I thought about changing the interpreter from Python to PyPy, however, this does not help. You could read this comments branch: http://codeforces.com/blog/entry/44106?#comment-287483
•  » » » » 4 years ago, # ^ | ← Rev. 2 →   0 what does "Your code is overly controlled. " mean?
•  » » » » » 4 years ago, # ^ |   0 Don't know. Could you, please, post the entire message? My message was about unsupported language.
•  » » » » » » 4 years ago, # ^ |   0 I got it... it is for problem E and mean I used the keywords that I didn't have to use
 » 4 years ago, # |   +7 Today I learned how to get a pointer from a label in GCC to implement if without the usual keywords. I want to unsee that, but I can't...
•  » » 4 years ago, # ^ |   +11 I thought about this idea for a moment but luckily I found a better way. std::for_each and std::max/std::min` to the rescue!
 » 4 years ago, # |   +2 Guess，Guess，write，write，and I always got an WA
 » 4 years ago, # |   0 We can use Ruby to solve E easily. 'if' can be replaced by 'unless' while '1.upto(n)' or '(1..n).each' for 'for'