### Блог пользователя Lewin

Автор Lewin, история, 13 месяцев назад, ,

Hello everyone!

Another year has gone by. The last Codeforces contest of this year will be tomorrow, 29 Dec, 15:35 UTC.

The round details:

• combined div1+div2
• 8 problems
• 2.5 hours
• rated!!!

I'd like to thank the following people for helping with the round: KAN, winger, AlexFetisov, zemen, xiaowuc1, MikeMirzayanov. Without them, this round would not have been possible.

Scoring distribution will be posted later. Make sure to read ahead on the problems, since there may be some later problems that are easier for you. I hope to see you all at the contest, and good luck on the last chance to increase your rating this year!

EDIT1: The scoring distribution is 500-750-1000-1750-1750-2000-2750-3500

EDIT2: There will be a five minute delay for starting.

EDIT3: Editorial is here: http://codeforces.com/blog/entry/56713

EDIT4: Congratulations to the winners!

•
• +1310
•

 » 13 месяцев назад, # |   -54 Is it rated or not?
•  » » 13 месяцев назад, # ^ |   0 yes is rated!!!! , this is clarificated in the round details.
•  » » » 13 месяцев назад, # ^ | ← Rev. 2 →   -21
•  » » » » 13 месяцев назад, # ^ |   0 how can i post a picture XD!!!
•  » » » 13 месяцев назад, # ^ |   +13 Take it easy! He is just doing his best to get highest downvote this year! It's going to be the last chance! :))
 » 13 месяцев назад, # |   +61 Be careful, you wrote "17:35 UTC" instead of "15:35 UTC".
•  » » 13 месяцев назад, # ^ |   +28 Thanks for the catch. It's fixed now.
•  » » » 13 месяцев назад, # ^ |   -44 HEY IS IT RATED???
•  » » » 13 месяцев назад, # ^ |   -43 HEY WHY ARE YOU NOT REPLYING??? I WANT OFFICIAL ANSWER
•  » » » » 13 месяцев назад, # ^ |   0 It's rated... don't you see the last line of the round details..??
•  » » » 13 месяцев назад, # ^ |   +21 lewin realization for 2018: "Don't mess up with contests date/time".
•  » » » » 13 месяцев назад, # ^ |   +14 I need to work on it ;) Thankfully someone caught it this time.
•  » » 13 месяцев назад, # ^ |   -21 I've wondered are cf names case sensitive?I read your name as "Noe Inadal" (when it is clearly Noel Nadal)
•  » » » 13 месяцев назад, # ^ |   0 Wat
•  » » » » 13 месяцев назад, # ^ |   -11 It's ok, I just checked.Noe it is not.
 » 13 месяцев назад, # |   +11 Expert this contest!! Good luck to all and have fun, hopefully 7k will participate. Thanks Mike for everything this year.
 » 13 месяцев назад, # |   +13 Mathematically speaking, would the ratings of Div2 participants be affected in any way in a Div1 + Div2 contest as opposed to only Div2 contests?
•  » » 13 месяцев назад, # ^ |   -32 We don't even know if it's rated or not yet.
•  » » » 13 месяцев назад, # ^ |   0 It is, check the last bullet point
•  » » » » 13 месяцев назад, # ^ |   -36
•  » » » » » 13 месяцев назад, # ^ | ← Rev. 3 →   -11 Weird
•  » » » » » » 13 месяцев назад, # ^ |   -23 I think it's not rated for me
 » 13 месяцев назад, # |   -41 "Make sure to read ahead on the problems, since there may be some later problems that are easier for you." — smelling something fishy. Hoping it will a be memorable contest.
•  » » 13 месяцев назад, # ^ |   -32 And rated...
•  » » » 13 месяцев назад, # ^ |   -18 It is rated!!!!
 » 13 месяцев назад, # |   +37 What does the Good Bye contest say: "Long time no C"
•  » » 13 месяцев назад, # ^ |   -33 Haha it was so funny that I forgot to laugh.
•  » » » 13 месяцев назад, # ^ | ← Rev. 2 →   +10 This blog enetry was post 45 mins ago and you already commented 8 times... this is funny for me
 » 13 месяцев назад, # | ← Rev. 2 →   0 "Make sure to read ahead on the problems, since there may be some later problems that are easier for you"Love the suspense! Can't wait!
•  » » 13 месяцев назад, # ^ |   -12 B is tougher than D lol.
 » 13 месяцев назад, # | ← Rev. 2 →   +14 Can't wait to participate the contest, if I don't drop to div2 I can then finally propose a CodeForces contest. :DNote to self: Don't stay overnight for a programming contest ever again.... ZzzzzZZZZzzzz
•  » » 13 месяцев назад, # ^ |   -28 Well, will that contest be rated?
•  » » 13 месяцев назад, # ^ |   +1 You can propose a contest if you are expert.
•  » » » 13 месяцев назад, # ^ |   0 Except it would take me another 15 contests to propose one. :/
•  » » » » 13 месяцев назад, # ^ |   0 Serious question, do they give priority to Div1 problemsetters over Div2? If so I didn't know.
•  » » » » » 13 месяцев назад, # ^ |   +27 I don't know, but they probably give higher priority to high quality questions?
•  » » » » » 13 месяцев назад, # ^ |   +12 According to the coordinator, proposals are reviewed in "the order in which they appear on the list," which is most probably chronological order, I suppose.
 » 13 месяцев назад, # | ← Rev. 2 →   -13 This was a fun contest,let’s have more combined contests!
 » 13 месяцев назад, # |   0 Wish everybody high rating in the last contest in this year and good holiday mood!
•  » » 13 месяцев назад, # ^ |   -28 Why are wishing high rating in a not rated contest.
•  » » » 13 месяцев назад, # ^ |   +1 Have you gone mad? Why couldn't you see that this is a rated contest!!! It is written clearly on the post. Stop irritating peoples with your irrelevant comments.
•  » » 13 месяцев назад, # ^ |   -7 You too!
•  » » 13 месяцев назад, # ^ |   +9 Mathematically, "everyone" can't have a rating increase :(
•  » » » 13 месяцев назад, # ^ |   +5 what if everyone got the same place as their rating points rank?
•  » » » » 13 месяцев назад, # ^ |   +4 2 people can have the same rating but not the same rank, so it still can't happen.
•  » » » » » 13 месяцев назад, # ^ |   +3 they can if they get same exact scored
•  » » » » » » 13 месяцев назад, # ^ |   0 Does it matter if they have different ratings. Will rating change though?
•  » » » 13 месяцев назад, # ^ |   +36 Wish everyone "non-decreasing" rating!
•  » » » » 13 месяцев назад, # ^ |   -34 Wish everyone " increasing " rating !
•  » » » » 13 месяцев назад, # ^ |   -42 Wish me increasing rating! I don't care about other persons' ratings.
•  » » » » » 13 месяцев назад, # ^ |   +18 Wish you increasing rating!
 » 13 месяцев назад, # |   +5 Happy new year codeforces !
 » 13 месяцев назад, # |   -23 Will the ratings be calculated separately for div 1 and div2 even though we are in the same contest? I feel that, unless rating changes are calculated differently, div 2 participants will be less likely to gain rating if they are in the same pool as div 1 participants.
•  » » 13 месяцев назад, # ^ |   0 that just means div1 people gain more rating!
•  » » 13 месяцев назад, # ^ | ← Rev. 2 →   +42 I think otherwise. As the cf rating formula uses rank/(expected rank) as rating change coefficient, Div. 2 participant's are expected to be after div1 ones, so if they do a bit well they could get way bigger change that normal div.2. But if div1 gets beaten by few div2 people he'll farther from first place whereas expected ranks stays the same. PS. Out of my experience I do get biggest changes on combined rounds.
•  » » » 13 месяцев назад, # ^ |   0 good or bad big changes?
•  » » » » 13 месяцев назад, # ^ |   +1 Good ;)
 » 13 месяцев назад, # |   +102 I hope 2017 ends making me a Specialist.
•  » » 13 месяцев назад, # ^ |   +80 What happened in 2015?
•  » » » 13 месяцев назад, # ^ |   +291 It was in queue.
•  » » 13 месяцев назад, # ^ |   +5 I believe in you. Don't let me down
•  » » » 13 месяцев назад, # ^ |   0 Will try my best.
•  » » » » 13 месяцев назад, # ^ |   0 :(A goal for 2018! :P
 » 13 месяцев назад, # |   +95 I bet for 10K+ Registrants! <3
•  » » 13 месяцев назад, # ^ |   +8 Last year there were 9.5k
•  » » » 13 месяцев назад, # ^ |   +1 It will be a bigger contest! Great!
•  » » » » 13 месяцев назад, # ^ |   +3 we beat last year by ~300 registrants...not a huge jump but progress none the less
•  » » 13 месяцев назад, # ^ |   +18 9.8K! Missed by 200, Will be ready next year with a few fake accounts :)
 » 13 месяцев назад, # |   0 So what's your New Year's Resolution ?
•  » » 13 месяцев назад, # ^ |   0 Try to get yellow. :/
•  » » » 13 месяцев назад, # ^ |   +61 Do. Or do not. There is no try
•  » » » » 13 месяцев назад, # ^ | ← Rev. 2 →   +10 May the (code)forces be with you, always.
•  » » » » » 13 месяцев назад, # ^ |   +12 may the code force be with you
•  » » » » » » 13 месяцев назад, # ^ |   +9 May the force code with you.
•  » » » 13 месяцев назад, # ^ |   0 You, will. You are gonna be the next great from India :)
•  » » 13 месяцев назад, # ^ |   +4 DIV1
•  » » 13 месяцев назад, # ^ |   +3 New year CF color changing to nutella so I can feel powerfull ;)
 » 13 месяцев назад, # |   +1 Are both div1 and div2 participants taken into consideration while calculating the rating change of a div2 guy?
•  » » 13 месяцев назад, # ^ |   0 Yes
 » 13 месяцев назад, # |   -11 Editorial right after the contest will be great, hope you will work on it.
•  » » 13 месяцев назад, # ^ |   0 better done than said.
•  » » » 7 месяцев назад, # ^ |   0 "With Great Power Comes Great Responsibility"
 » 13 месяцев назад, # |   -14 If this contest goes unrated MikeMirzayanov will give 100 + rating to everyone , Happy coding guys and girls !
•  » » 13 месяцев назад, # ^ |   +36 There is no point in rating if it's not earned.
•  » » 13 месяцев назад, # ^ |   -12 Rating is just a reflexion of your brain's state.
•  » » » 13 месяцев назад, # ^ |   +5 So true! Don't let just rating be the only ultimate motive of your problem solving.
 » 13 месяцев назад, # |   -7 So exciting! I still have a long way to go, hopefully 2018 will be better for me
 » 13 месяцев назад, # | ← Rev. 3 →   +2 How to solve D ? Update: I have mistakenly commented here. :p :p
•  » » 13 месяцев назад, # ^ |   +80
•  » » » 13 месяцев назад, # ^ |   +80 Please, do not use my profile image! Thanks :)
•  » » 13 месяцев назад, # ^ |   +1 hihihihihahahahaa
 » 13 месяцев назад, # | ← Rev. 4 →   +19 Restrations.. :p 2015 2016 2017 Pending.....
 » 13 месяцев назад, # | ← Rev. 2 →   +10 educational round rating update and goodbye 2017 will overlap :|PS: For the first time you can enter a round with a rating and end it with another one!
 » 13 месяцев назад, # |   +47 Probably lewin is thinking of a script such: if(comment.writer == "metsuka"){ GetRidOfThisComment(comment); } P.S. : baw bekesh biroooon!
 » 13 месяцев назад, # |   +13 LoL there is already another div2 contest in the new year!
 » 13 месяцев назад, # | ← Rev. 3 →   +3 Why still do not turn on New Year's magic?
•  » » 13 месяцев назад, # ^ |   0 was looking for that comment.. it's been a while since last I saw my name in red :)
•  » » 13 месяцев назад, # ^ |   0 maybe because it's not the new year yet
 » 13 месяцев назад, # |   +39 Codeforces is reliable, as usual...During virtual contest...
 » 13 месяцев назад, # |   +55 Considering that educational round's system-testing will happen during this contest , wouldn't it be too much of a load for the server since this contest is anyways going to have much more traffic that average?
•  » » 13 месяцев назад, # ^ |   -27 It's not your problem. Just worry if its going to be rated
•  » » 13 месяцев назад, # ^ |   +15 educational round testing will start after end of this contest. It was mentioned in it's blog.
 » 13 месяцев назад, # |   +22 Good luck everyone on the contest and in new 2018 year!I want to believe that codeforces will have less lags in next year then in this year!And also thanks to the guys who created an anime-contests, they was really good. I want more anime-contests in the future, does anyone else want it too?
•  » » 13 месяцев назад, # ^ |   -31 No anime sucks
•  » » » 13 месяцев назад, # ^ |   +8 NANI?
•  » » » » 13 месяцев назад, # ^ |   -6 WEEBS.....
•  » » » » » 13 месяцев назад, # ^ |   +5 Butthurt is not good reason for bad attitude.http://codeforces.com/blog/entry/54234
 » 13 месяцев назад, # |   +2 Will we be able to change our handles this year?
 » 13 месяцев назад, # | ← Rev. 2 →   +33 My rating changes at Good bye contest: Good bye 2014: -114 Good bye 2015: -28 Good bye 2016: -71 Good bye 2017: -???
•  » » 13 месяцев назад, # ^ |   0 +129
•  » » 13 месяцев назад, # ^ |   +5 Starting new year with less rating doesn't feel like a good bye from 2017 :(
•  » » 13 месяцев назад, # ^ | ← Rev. 2 →   +86 Your expression, that is:Good bye yy: yy*21.5-43382.75-(-1)^(yy)*32.25So, Goodbye 2017 you will get 15 increasing rating.
 » 13 месяцев назад, # |   0 Won't the questions sorted by difficulty like in regular contests?
 » 13 месяцев назад, # |   +10 Good luck to all the participants! I hope all the participants will get high rating! Happy New Year 2018!!!
 » 13 месяцев назад, # |   +89 I guess there must be a question on tree(Christmas tree)
•  » » 13 месяцев назад, # ^ |   +63 There is a comment for 2 year ago.
 » 13 месяцев назад, # |   +2 Good luck. Have fun!
 » 13 месяцев назад, # | ← Rev. 2 →   0 I wonder if there are T-shirts for the well-performed?I'm looking forward to that!
 » 13 месяцев назад, # |   +12 We are waiting for Scoring distribution
 » 13 месяцев назад, # |   +34 The contest is combined for both divisions The red contestants:
•  » » 13 месяцев назад, # ^ |   +59 me too
•  » » » 13 месяцев назад, # ^ |   +98 There is a comment for last year.
•  » » 13 месяцев назад, # ^ |   +40 And the green contestants be like
•  » » » 13 месяцев назад, # ^ |   0 they have all the colours, though
 » 13 месяцев назад, # |   0 4500 registrations and 8.5 hours left. I think we'll have at least 8.000 participants. I hope that the site will work
 » 13 месяцев назад, # |   -19 祝大家元旦快乐！
 » 13 месяцев назад, # |   +2 Happy new year Codeforces!!!
 » 13 месяцев назад, # |   +1 scoring distribution will be 500-750-1000-1500-2250-3000-3250-3500.
 » 13 месяцев назад, # |   0 is there any possibility to change cf handle ?
 » 13 месяцев назад, # |   0 happy new year guys in advance and marry christmas guys <3
 » 13 месяцев назад, # |   0 а во время раунда фаза взломов на эдакейшене будет открыта получаеться во время раунда будут начисляться рейтинг для тех кто участвовал на эдакейшене ? или после ?
 » 13 месяцев назад, # |   +56 Let's hope we can see the fight between tourist and moejy0viiiiiv
•  » » 13 месяцев назад, # ^ |   -11 I want to see tourist vs Petr
•  » » » 13 месяцев назад, # ^ |   0 It's like Messi vs Ronaldo :D
•  » » » » 13 месяцев назад, # ^ |   0 Not interested at all...
 » 13 месяцев назад, # |   +6 Will magic color effect be activated this year ?
•  » » 13 месяцев назад, # ^ |   -6 Yes
 » 13 месяцев назад, # |   +39 ░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ ░░░░░░░░░░░░░░░░░░░░██░░░░░░░░░░░░░░░░░░░░ ░░░░░░░░░░░░░░░░░░██████░░░░░░░░░░░░░░░░░░ ░░░░░░░░░░░░░░░░░█████████░░░░░░░░░░░░░░░░ ░░░░░░░░░░░░░░░████████░███░░░░░░░░░░░░░░░ ░░░░░░░░░░░░░░█████████░░███░░░░░░░░░░░░░░ ░░░░░░░░░░░░░███████████░░░██░░░░░░░░░░░░░ ░░░░░░░░░░░░██████████░░░░░░██░░░░░░░░░░░░ ░░░░░░░░░░██████████░░░░░░░░░██░░░░░░░░░░░ ░░░░░░░░░░█████████░░░░░░░░░░░██░░░░░░░░░░ ░░░░░░░░░█████░░░░░░░░░░░░░░░░░██░░░░░░░░░ ░░░░░░░░████████░░░░░░░░░█████░██░░░░░░░░░ ░░░░░░░░░░░███████████████████░░░░░░░░░░░░ ░░░░░░░░░░░████████████████████░░░░░░░░░░░ ░░░░░░░░░░██████████████████████░░░░░░░░░░ ░░░░░░░░░████████████████████░░██░░░░░░░░░ ░░░░░░░░████████████████████░░░░██░░░░░░░░ ░░░░░░░████████████████░░░░░░░░░░██░░░░░░░ ░░░░░░████████████░░░░░░░░░░░░░░░░██░░░░░░ ░░░░░████░░██░░░░░░░░░░░░░░░░░░░░░░██░░░░░ ░░░░███████░░░░░░█████░░░░░░█████████░░░░░ ░░░░██░░████████████████████████░░░░░░░░░░ ░░░░░░░█████████████████████░░░██░░░░░░░░░ ░░░░░░███████████████████░████░░░██░░░░░░░ ░░░░██████████████████████░░░░░░░░░██░░░░░ ░░██████████████████████░░░░░░░░░░░░███░░░ ░███████████████░█░░░░░░░░░░░░░░░░░░░░██░░ █████████░█░░░░░░░░░░░░░░░░░░░░░░░███████░ ░░░░░░░███░░░░░░░███████░░░░░░██████░░░░░░ ░░░░░░░░███████████████████████████░░░░░░░ ░░░░░░███████████████████████████░██░░░░░░ ░░░░██████████████████████████████░███░░░░ ░░░█████████████████████████████░░░░░██░░░ ░░█████████████████████████░░░░░░░░░░░██░░ ░█████████████████████░█░░░░░░░░░░░░░░░██░ █████████████████░█░░░░░░░░░░░░░░░░░░░████ ░░░░░███████████░░░░░░░░███░░░░████████░░░ ░░░░░░░░░░░░░░░░███░█████░█████░░░░░░░░░░░ ░░░░░░░░░░░░░░░░████████░░░░░░░░░░░░░░░░░░ ░░░░░░░░░░░░░░░░██████░█░░░░░░░░░░░░░░░░░░ ░░░░░░░░░░░░░░░░██████░█░░░░░░░░░░░░░░░░░░ ░░░░░░░░░░░░░░░░█████░░█░░░░░░░░░░░░░░░░░░ ░░░░░░░░░░░░░░░░████░░░█░░░░░░░░░░░░░░░░░░ ░░░░░░░░░░░░░░░░████████░░░░░░░░░░░░░░░░░░ ░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ ░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ ░░░░░░███████░░████████░░██░░███████░░░░░░ ░░░░░░░░░░░██░░██░░░░██░░██░░██░░░██░░░░░░ ░░░░░░░░░░░██░░██░░░░██░░██░░██░░░██░░░░░░ ░░░░░░███████░░██░░░░██░░██░░███████░░░░░░ ░░░░░░██░░░░░░░██░░░░██░░██░░██░░░██░░░░░░ ░░░░░░██░░░░░░░██░░░░██░░██░░██░░░██░░░░░░ ░░░░░░███████░░████████░░██░░███████░░░░░░ ░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░ ONE MORE TIME HAPPY NEW YEAR !!!!!!!!!!!!!!!!
 » 13 месяцев назад, # |   0 Can i change my handle?
•  » » 13 месяцев назад, # ^ | ← Rev. 2 →   -6 Yes. But you can only change your handle during January 1 to January 10 in each year, as a new year gift!
•  » » » 13 месяцев назад, # ^ |   0 are U sure?
•  » » » » 13 месяцев назад, # ^ | ← Rev. 2 →   +5 Yes, see this post of MikeMirzayanov: New Year Tradition: You can change handle up to January 10th
•  » » » » 13 месяцев назад, # ^ |   +29 U is just a letter, so it can't be sure or unsure.
 » 13 месяцев назад, # |   -10 So, all the 8 problems are set by lewin and the others who are mentioned in the post just helped to prepare the round, not setters, right? WOW ! Great !!
•  » » 13 месяцев назад, # ^ |   -33 He probably copied problems from the internet.
 » 13 месяцев назад, # |   +1 Wish a color-change round!
•  » » 13 месяцев назад, # ^ |   +3 maybe to blue :) i prefer being blue !
•  » » » 13 месяцев назад, # ^ |   +8 the same here :P
•  » » » » 13 месяцев назад, # ^ | ← Rev. 2 →   0 Guess my dream came true! ^_^(though it's only gonna last 'til 10th Jan :/)
 » 13 месяцев назад, # |   0 Rush to purple or higher :)
•  » » 13 месяцев назад, # ^ |   0 is that possible in codeforces rules? i mean going two levels up using one contest
•  » » » 13 месяцев назад, # ^ |   0 I think a lot of people jumped from candidate master straight to international master by getting around top 50 in a div1 contest.
 » 13 месяцев назад, # |   0 Is it advisable for a contestant who gets around 1000 rank in Div2 contests to participate in combined (Div1 + Div2) rounds?
•  » » 13 месяцев назад, # ^ |   +27 It's advisable for any contestant to participate in any round.
•  » » 13 месяцев назад, # ^ |   0 The goodbye contests are the best ever contests of codeforces ,i absolutely advice every programmer to participate in it
 » 13 месяцев назад, # |   +5 another goodbye contest , great =)
 » 13 месяцев назад, # |   +8 This is such a big contest! Feel a little nervous:)Try my best to get a good ending of 2018.Hope everyone will have a good ending in 2017 and get a higher rating in 2018.
 » 13 месяцев назад, # |   0 Can every contestant get +50 without reason as a new year motivation gift? :D MikeMirzayanov
•  » » 13 месяцев назад, # ^ |   +21 Mike is not Santa
•  » » » 13 месяцев назад, # ^ | ← Rev. 2 →   -10 He could be real Santa! No one knows and you are on his naughty list.
 » 13 месяцев назад, # |   -6 Open Hacking in the last EDUCATIONAL ROUND + System Test on EDUCATIONAL ROUND + Handling 10,000 participants in GOOD BYE 2017 Contest. REST IN PEACE CODEOFORCES SERVERS
 » 13 месяцев назад, # | ← Rev. 4 →   +99 for CF-Predictor users:Rating prediction for Good Bye 2017 wouldn't be as accurate as always, because previous educational round not judged yet, so div2 users that participate in it have unknown rating. I decided to use predicted ratings from educational contest as initial for Good Bye 2017.===================================================================Good luck & high rating and Happy New Year!===================================================================Предсказание рейтинга для Good Bye 2017 к сожалению будет не таким точным, как обычно, потомучто до сих не проведена финальная проверка последнего educational раунда. Таким образом у участников educational раунда (из второго дивизиона) не известный рейтинг на момент начала Good Bye 2017. Я решил, в качестве апроксимации начального рейтинга перед сегодняшним контестом взять предсказания по educational раунду. Надеюсь, что расхождение будет не очень значительным:)
 » 13 месяцев назад, # |   0 If the sys test process is programmed to start automatically right after the educational round end, don't forget to disable it, or we will be getting 2 hours queue.
 » 13 месяцев назад, # |   0 Can i cancel registration?
•  » » 13 месяцев назад, # ^ | ← Rev. 2 →   -14 there is no option (false statement) , but if you won't participate (do not submit anything) rating wont change.
•  » » 13 месяцев назад, # ^ |   0 go to the contest participants list, find your name, click the red X
•  » » » 13 месяцев назад, # ^ |   0 Thank you!
 » 13 месяцев назад, # |   0 Is 2.5 hours enough for 8 problems to solve? Thanks!
 » 13 месяцев назад, # |   -10 I lost a girl recently ,so I hope I could do better in codeforces....
•  » » 13 месяцев назад, # ^ |   +23 from your basement ?
•  » » 13 месяцев назад, # ^ |   0 Do whatever you want but not bomb America for god's sake
•  » » 13 месяцев назад, # ^ |   +2 How can you say that :( Gold_Three_Fat I_LOVE_EVERY_GIRL
•  » » 13 месяцев назад, # ^ |   0 My bad friend login my account and do some bad thing！！！
 » 13 месяцев назад, # |   +1 I'm anticipating a lot of math problems. Everytime lewin organizes a round, there are plenty of beautiful math problems that I always fail on :(
 » 13 месяцев назад, # |   +3 But... it's not even december 31st..
 » 13 месяцев назад, # |   +13 Hope for shorter statements :)
 » 13 месяцев назад, # | ← Rev. 2 →   0 I hope it's not goodbye for 2017, but goodbye for current rate and Welcome for new Rate and new Div
 » 13 месяцев назад, # |   0 Happy new year !!! In this 2018 I hope that we will be better than last year, and of course I wish good luck to the all contests in 2018.
 » 13 месяцев назад, # |   0 After a long time contest=(Div1 + Div2)! :p
 » 13 месяцев назад, # |   +131 CF new winner moejy0viiiiiv !!!
•  » » 13 месяцев назад, # ^ |   +9 What I see:
•  » » 13 месяцев назад, # ^ |   0 So we go die together :)
 » 13 месяцев назад, # |   +12 Goodbye Div 1 Contest. :|
 » 13 месяцев назад, # |   +5 are we going to see first 10k participation :D
 » 13 месяцев назад, # |   0 well,hope i'll gain some rating.
 » 13 месяцев назад, # |   +83 Waiting for around 15 minutes to post this. Have Fun
 » 13 месяцев назад, # | ← Rev. 2 →   0 so this year we have 9k+ registered users for this contest. i thought maybe it will cross 10k. but nevermind, all the best guys.
 » 13 месяцев назад, # |   +32 Goodbye Candidate Master. Hello Expert. :P
 » 13 месяцев назад, # |   0 in queue :| right before contest :|
 » 13 месяцев назад, # | ← Rev. 2 →   +61 Will there be a delay to reach 10K?UPD: as expected the first 5 mins delay :"D
•  » » 13 месяцев назад, # ^ |   0 Congratulations. Your wishes is granted
 » 13 месяцев назад, # |   0 Good luck, everyone!
 » 13 месяцев назад, # |   +36 It is Delayed to reach 10K :D
 » 13 месяцев назад, # |   +11 Have been while to see delays...
 » 13 месяцев назад, # |   +11 "you may click the link to enter the contest area"never been so deceived in my life :(
 » 13 месяцев назад, # |   0 Did anyone else get 0:00 on timer and contest not yet started message??
•  » » 13 месяцев назад, # ^ |   0 Contest was delayed
 » 13 месяцев назад, # |   0 What will the rating change base on? My current rating or my rating after edu. round?
•  » » 13 месяцев назад, # ^ |   0 After educational round
 » 13 месяцев назад, # |   +5 HOpE there will be no problem like site not available :/
 » 13 месяцев назад, # | ← Rev. 3 →   -6 Codeforces is slow right now. :(UPD - Seems fine now :)
 » 13 месяцев назад, # |   +12 the server is acting up again
 » 13 месяцев назад, # |   +18 dafuq is this contest :(
•  » » 13 месяцев назад, # ^ |   +14 It's all math and geometry (aka my nightmare).
 » 13 месяцев назад, # | ← Rev. 2 →   +14 seems like it's DIV 1 + DIV 1.52017
 » 13 месяцев назад, # | ← Rev. 9 →   +111 I hate this contest so much. First three problems are as easy as it could be, they are just stupid, not for the codeforces, and then just wtf.I mean, usually people easily make a smooth transition from simple problems to hard problems, what the hell happened to the authors this time? There is even nothing to hack.
•  » » 13 месяцев назад, # ^ |   +9 Third one is easy if you have any idea about geometry, which I don't.
•  » » » 13 месяцев назад, # ^ |   0 If you don't know geometry, use a binary search by answer :)
•  » » » » 13 месяцев назад, # ^ |   0 that gave me 3 TLE's
•  » » » » » 13 месяцев назад, # ^ | ← Rev. 2 →   +3 When you do binary search on doubles, you might want to consider stopping after a certain number of steps instead of when left and right are (almost) equal. i.e. do for(int step=0; step<50; ++step) { ... } instead of while(right - left > eps) { ... }. I modified this in your code and "upgraded" it (if you can call it that) from a TL on test 4 to a WA on test 7.quick EDIT: I looked over your code a little bit more and fixed this line: return (one * one + two * two) < (twoR * twoR + EPS); to this: return (one * one + two * two) <= (twoR * twoR);... and got accepted. (In general) Don't use eps for comparisons, only for checking equality. So in principle binary search works, you just need to know how to work with doubles :P
•  » » » » » » 13 месяцев назад, # ^ |   0 Cool, thank you for your help!
•  » » 13 месяцев назад, # ^ |   +19 You know what to do, do you?
•  » » 13 месяцев назад, # ^ |   0 Arguably,I think problem A is easy for any contestant,and too easy for contestants like you,however, its level of difficulty would be equivalent to any previous A problems,but the test cases ruined the trick that many people may fail on in sense that it made the problem statement too obvious,so, problem A had a nice logical trick but it could be made more competitive than that, it was more of logical puzzle than competitive programming problem
•  » » 13 месяцев назад, # ^ | ← Rev. 2 →   0 Have you read F?
 » 13 месяцев назад, # | ← Rev. 2 →   +1 The problem provider use Math f**k me.
 » 13 месяцев назад, # |   0 good bye 2017, happy new year every1
 » 13 месяцев назад, # |   0 If I submit 2 solutions and both clear the pretest will I still face a penalty of 50 points During this contest me second solution which I submitted after 4 min of the first sol my score was approximately 50 less
•  » » 13 месяцев назад, # ^ |   +2 Resubmission gets you penalty every time except compilation error or wrong answer on sample 1.
•  » » » 13 месяцев назад, # ^ |   0 even if both sol are correct and accepted? Thanks
•  » » » » 13 месяцев назад, # ^ |   0 Yes. Even more: if you got accepted and then WA, your WA will be scored (I'm not sure if that's true if the WA fails pretests, but it definitely is true if both solutions passed the pretests: in that case, your last submission is considered to be your choice).
•  » » » » » 13 месяцев назад, # ^ |   0 ohhh.Tysm as I didn't knew about this as I am new to this platform
•  » » 13 месяцев назад, # ^ |   0 In the score table, you can see each resubmission is -50. Only the last submission that passes pretests will be judged. Everything else will be ignored.So, yes, you still get a penalty.
•  » » 13 месяцев назад, # ^ |   0 Yes, you will face a penalty of 50 points, similar thing happened with me.
 » 13 месяцев назад, # |   -6 I don't understand why my submission for 2C fails pretest#1 even though it matches the output in the problem statement :S
•  » » 13 месяцев назад, # ^ |   -7 Check your precision
•  » » » 13 месяцев назад, # ^ |   0 15 decimal points ..
•  » » » » 13 месяцев назад, # ^ | ← Rev. 2 →   0 Check if any debugging statements are being executed.
•  » » » » » 13 месяцев назад, # ^ |   0 Thank you! That was it, silly debugging statements clogging the output ..
•  » » » » » » 13 месяцев назад, # ^ |   0 Yeah happened many times with me.Try not to repeat the mistake.
•  » » 13 месяцев назад, # ^ |   0 go to custom invocation and test the test
•  » » » 13 месяцев назад, # ^ |   0 Thanks for the tip it helped me find the problem
 » 13 месяцев назад, # |   -7 To-whoever-is-reading-this-Happy-New-Year--wish-you-the-best-this-year
 » 13 месяцев назад, # |   +38 Am I alone who's hating this fucking "Expected number" ? :/
•  » » 13 месяцев назад, # ^ |   +4 I usually like this kind of problems, though, I suppose, many of contestants never solved this problems, but this time it's something beyond common sense.
 » 13 месяцев назад, # |   +34 good bye 2017 && rating
 » 13 месяцев назад, # |   +103 What’s up dotorya, I am koosaga from South Korea. I’m a huge fan of you. You were 2nd in Facebook Hacker Cup 2017, your team was a Grand Champion at ICPC Daejeon 2017, you and your team continued to amaze Petr for a long time. It is unbelievable. I think your team will be a champion at ICPC WF 2018. I’m doing CP for 4 years and still I’m not like you. I want to improve my skill and be a great competitive programmer like you. How can I be a great competitive programmer like you? What is your training method?? Do you have any secret tips???? Please answer my question. Thanks in advance.
•  » » 13 месяцев назад, # ^ | ← Rev. 2 →   +10 (+ I was writing this 15 minutes before the contest ends, and I'm so sad that Petr got first place — no personal feelings, but it's more fun to troll dotorya when he is in first place)
•  » » » 13 месяцев назад, # ^ |   +20 I have same questions for you :) . How can I be a great competitive programmer like you? What is your training method?? Do you have any secret tips???? Please answer my question. Thanks in advance.
•  » » » » 13 месяцев назад, # ^ |   +134 You are not my huge fan, so I won't tell you my secret tips
•  » » » » » 13 месяцев назад, # ^ |   +24 팬이에요
•  » » » » » 13 месяцев назад, # ^ |   +18 팬이에요!!
•  » » » » » 13 месяцев назад, # ^ |   0 I'm big big big fan of you.
•  » » » 13 месяцев назад, # ^ |   +5 Yep me too(I have been recently following dotorya and he's awessome). But I was sadder before for that Petr would be losing his place for the silliest reason possible. And actually that last minute manoeuvre by Petr made the contest twice as much fun to watch.
•  » » » » 13 месяцев назад, # ^ | ← Rev. 2 →   0 I didn't thought that he will lose his first place, but it really happened. Amazing piece of sports :DHowever, I don't know why Petr gained +250 from the Hack. AFAIK He should only gain +200. (3 * 100 — 2 * 50) (UPD : It was fixed somehow)
•  » » » » » 13 месяцев назад, # ^ |   +59 The last hack happened 1 second after the end of the contest.
•  » » » » » » 13 месяцев назад, # ^ |   0 Yup I thought you should get +3 -2, but somehow it was written like +3 -1 (-1) and the one from 147:02 didn't count. That was what happened when I took screenshot, but it was resolved right after I wrote the reply. Sorry for the confusion :/
•  » » » » » » 13 месяцев назад, # ^ | ← Rev. 2 →   +35 for Petr even time slows down. and a black hole is created,
•  » » » » » 12 месяцев назад, # ^ |   0 hey, can I talk to u please, ??
 » 13 месяцев назад, # |   0 Что не так с моей С? http://codeforces.com/contest/908/submission/33787695
•  » » 13 месяцев назад, # ^ |   0 r, x даны в условии целыми, первые операции сравнения (нужно ли обновлять y у круга через другой нужно проводить в целочисленных операциях)
 » 13 месяцев назад, # |   +6 What is the solution for F?
 » 13 месяцев назад, # |   +5 Is F an analysis of various cases ?
•  » » 13 месяцев назад, # ^ |   0 what is test case 4 of F?!
•  » » » 13 месяцев назад, # ^ |   0 test 4 is probably you need to make a cycle. something like. GRBRBRBG
•  » » 13 месяцев назад, # ^ |   0 i have a pretty simple greedy. Claim1: Answer is a spanning tree in most cases.(I Will describe corner case later) Claim2: Green component is connected by itself Now its pretty easy to see that after connecting Green with a chain , we need to connect reds and blues between 2 greens in a block with a chain sort of thing(We leave out the biggest gap here) Corner case (instead of connected 2 consecutive greens with a chain and reds and blues with spanning tree , we can instead make a cycle , ie connected green -> red -> red -> ... -> red -> green and green -> blue -> blue -> ... -> blue -> green).
•  » » » 13 месяцев назад, # ^ |   0 I missed the cycle!! Test 4!! T-T
•  » » 13 месяцев назад, # ^ |   0 Yes it is, and it is the worst type of question for a sleepy programmer to pick up in a contest. :/
 » 13 месяцев назад, # | ← Rev. 2 →   0 Hack for C. 5 21 10 7 3 6Output: 2.000000000 2.000000000 4.645751311 5.464101615 8.518734657
•  » » 13 месяцев назад, # ^ |   +3 What is the correct answer for this case? FazleRahmanEjazi
•  » » 13 месяцев назад, # ^ |   0 What is expected answer?
•  » » 13 месяцев назад, # ^ |   +3 What should answer be?My code gives 2 2 4.64575 5.4641 8.51873
•  » » 13 месяцев назад, # ^ | ← Rev. 2 →   0 Mine was:3 100100 299 100
•  » » 13 месяцев назад, # ^ |   +4 My code gives 2 2 4.64575131106 4.64575131106 8.51873465727
 » 13 месяцев назад, # | ← Rev. 3 →   -39 edit since I've calmed down slightly If you are going to write problems, PLEASE make sure that if you find the optimal solution, you will get the problem right instead of having to fiddle around forever with random implementation details. There is no purpose in having contestants sit around trying to reimplement standard data types or come up with increasingly "creative" (re: sketchy) ways to get around overflow or try to shave off constant factors, at least in a purportedly algorithms-based contest. Whether you implement this by increasing the time limit or setting the problems limits to something more reasonable (k=1000 is just unnecessary considering the normal Python implementation runs fine with k=500 or so) doesn't really matter, but shifting the focus away from algorithms and onto constant time improvements really defeats the purpose.
•  » » 13 месяцев назад, # ^ |   +21 I don't believe the problem is intended for you to implement fractions, but work with modular arithmetic by calculating the modular inverses by means of FLT or Euclidean algorithm.
•  » » » 13 месяцев назад, # ^ |   -16 Well, official solution reimplements fraction data type, so I think this was intended. Of course modular inverses are a very easy solved problem that is used only at the end.
•  » » » » 13 месяцев назад, # ^ | ← Rev. 2 →   +5 I read the solutions, and it has no mention of implementing fraction data type. What I mean by working with modular inverses is you don't ever need to work with fractions at all. Instead of a / b use and you obtain the same result, not just the last calculation. With the number of prime factors you can include as part of your input, overflow is bound to happen.See for yourself : 33784912
•  » » » » » 13 месяцев назад, # ^ |   -19 Ok, it is possible that I'm misreading the official solution and there is some graceful way of handling overflow. This isn't really my main point though; I don't care much about whether overflow exists supposing there is a simple way of dealing with it. My main concern/complaint is that doing this problem in Python is evidently practically impossible even with the optimal solution (there are no accepted solutions in Python), and considering that this could have been remedied with a trivial tweak to the limits (that wouldn't allow solutions of suboptimal time complexity), it seems that this was done intentionally which I cannot understand the purpose of.
•  » » » » » » 13 месяцев назад, # ^ | ← Rev. 2 →   +5 Well then I don't understand you. The reason your Python solution probably failed is because you allowed the size of your factors to become so large they consume too much time per multiplication, addition, etc. You obviously should have evaluated the time and realised this solution is not practical. I was unaware Python does not support modulo calculations (sarcasm).
•  » » » » » » » 13 месяцев назад, # ^ | ← Rev. 2 →   -14 I suppose we will have to agree to disagree then -- in my view the implementation is essentially just a means of proving one's solution, and choosing limits so that implementations in some languages are essentially not possible (at least without a lot of constant time twiddling) seems to me to place the focus off of problem solving, which in theory is what these contests aim at. But as I said, I can understand that others will have different interests and will prefer these types of constant-optimization challenges. Of course thanks for your opinion.
•  » » » » » » » » 13 месяцев назад, # ^ |   +9 So to summarise your point, you believe big-Num multiplication is "constant time twiddling"? Because I doubt your solution fails by only a constant factor.
•  » » 13 месяцев назад, # ^ | ← Rev. 2 →   -18 I see now official solution is to give wrong fraction but one which gives same final answer. Ok, I guess it is possible to figure out this "trick" during contest, but IMO solving the problem should be the important part of the problem and if limits are chosen so that the official solution cannot be implemented (basically word for word) in Python then something is fundamentally wrong with the writing approach. Of course I understand that everyone's taste is different and some people prefer to optimize constant factors, but IMO this isn't really what these kinds of contests are for.
•  » » 13 месяцев назад, # ^ |   +1 "come up with increasingly "creative" (re: sketchy) ways to get around overflow" : that's basically half of number-theoretic problems.
 » 13 месяцев назад, # |   0 how to solve D?
•  » » 13 месяцев назад, # ^ | ← Rev. 2 →   0 dp on number of abs x number of as. some straightforward math needed to avoid infinite sums when num ab + num a gets to be larger than k.
•  » » » 13 месяцев назад, # ^ |   0 please explain a bit more.
•  » » » » 13 месяцев назад, # ^ |   0 editorial explains my solution word for word basically, so just read that
 » 13 месяцев назад, # |   0 When you lock an answer and think to hack to jump up on the scoreboard, and you yourself get hacked. Crap :/ Never felt so helpless.
 » 13 месяцев назад, # |   +16 So I was reading problem E and I wondered if the intended solution used any kind of knowledge on algebraic structures, did anyone solve it like that?
 » 13 месяцев назад, # |   +4
 » 13 месяцев назад, # |   0 How to solve H ? I have a idea based on minimum clique partition in the graph of AND-components of size Unable to parse markup [type=CF_TEX], with edges corresponding to XOR constraints, but couldn't debug it in time.
•  » » 12 месяцев назад, # ^ |   -22 hey, talk to me please
 » 13 месяцев назад, # | ← Rev. 2 →   +14 What is an 'unsuccessful open hacking attempt', showing for Petr in the scoreboard?edit: now it doesn't show anymore
 » 13 месяцев назад, # |   +2 How to Solve D ?
•  » » 13 месяцев назад, # ^ |   +6 Notice that every time you place 'b' amount of subsequences "ab" increases by the current number of 'a' in the string. So dp[x][y] — answer if we have x 'a' in our string and y subsequences 'ab'. If x = 0, y = 0 then dp[x][y] = dp[x + 1][y] ('b' in the beginning of the string don't influence on the answer and we will place 'a' in one moment. The thing is that we can place many of 'a'. If x > k, then we will finish our process after first symbol 'b' will appear. So in this case we can add to dp[x][y] x + y(it will be in answer) and then add the expected amount of 'a' untill we will place 'b'. Denote the last one by E, so find it from the equation: .
•  » » » 13 месяцев назад, # ^ |   +5 Thanks
 » 13 месяцев назад, # | ← Rev. 2 →   0 The series for G seemed very 'fractal like'. How do you solve it?
 » 13 месяцев назад, # |   0 How to solve D,E,F?
 » 13 месяцев назад, # |   +34 goodbye rating 2017
 » 13 месяцев назад, # | ← Rev. 2 →   +3 I made 9 successful hacks during the contest. Let me explain what I found...For problem B, some implementations don't consider the last step. An example of hack is...2 2SE##0For problem C, some consider that the intersection will occur between the droping disk and the disk with max index (and, a disk with max y). Examples to both of them...3 1010 30 195 1010 10 50 49 30
•  » » 13 месяцев назад, # ^ |   0 Could you give the answers for your C test cases? mtkaya
•  » » » 13 месяцев назад, # ^ |   0 First test: 10.0000000 10.0