### ODT's blog

By ODT, history, 3 years ago,

Hello, Codeforces!

We are glad to invite you to participate in Codeforces Round #449 (both Div. 1 and Div. 2) which will be held on December 2, 17:05 MSK.

There are seven problems, created by mcfx, ODT, dogther.

This round is about the happiest girl in the world — Chtholly Nota Seniorious~!

You will help Chtholly, Nephren, Ithea and Willem (characters in the great novel and anime "What Do You Do at the End of the World? Are You Busy? Will You Save Us?") to solve some problems.

(Image by gin_sei56(・.8・) on pixiv)

This round is our first round on Codeforces.

Thanks to zcyskyaa for helping us, Arpa, cyand1317 and Tommyr7 for testing the round, gritukan and KAN for round coordination and MikeMirzayanov for Codeforces and Polygon platforms.

This round has 5 problems in each division and you have 2 hours to solve them.

The scoring will be announced shortly before the start of the contest.

The contest is rated for both Div. 1 and Div. 2 contestants.

It's recommended for both divisions to read through the Interactive Problems Guide before the round.

Wish everyone high rating and accepted submissions!

Upd: Scoring is 500-1000-1500-2000-2500

Upd2: Congratulations to the winners:

Div 1:

Div 2:

The editorial will be posted soon.

Upd3: Editorial

• +172

 » 3 years ago, # |   +1 Auto comment: topic has been updated by ODT (previous revision, new revision, compare).
•  » » 3 years ago, # ^ | ← Rev. 3 →   -12 I would solve 2E if there was a little more timeThe experience is so bad :(Problems are really goodHope there is no long queue next time
 » 3 years ago, # |   +46 Looks like an interesting round!
•  » » 3 years ago, # ^ |   +47 I agree with you.
•  » » » 3 years ago, # ^ |   -25 Is lxl rated?
•  » » » » 3 years ago, # ^ |   0 I feel that the round will be rated
•  » » » » 3 years ago, # ^ |   -11
•  » » » » » 3 years ago, # ^ |   -10 Too lazy coders use bits!
•  » » » » » 3 years ago, # ^ |   +9 Ohhh bro, First of all, check it for "Is it DATED" !
•  » » » » » 3 years ago, # ^ |   0 However,the round is semi-rated.lol
 » 3 years ago, # |   +60 Sounds like a poisonous round.
•  » » 3 years ago, # ^ |   -14 I think Round#447 is more poisonous! QAQ
•  » » » 3 years ago, # ^ |   +6 Really? Round #447 is interesting and fun,isn't it?
•  » » 3 years ago, # ^ | ← Rev. 4 →   +88 被删除的Tommyr7 20:45:30没有啊。。。div1E真的是字符串分治然后母函数然后FFT一下就做完了被删除的Tommyr7 20:45:39只是lxl表示你们知道也不会做，所以提前透露了Translate:Tommyr7Not at all...Solution for Div1E is just string divide and conquer then generating function and FFT Tommyr7lxl leaked it before the contest and said you can't solve it even if you know the problemUPD:This poisonous round must be unrated!
•  » » » 3 years ago, # ^ |   +63 Maybe only students from NS can solve this problem!
•  » » » » 3 years ago, # ^ | ← Rev. 2 →   0 What does this have to do with ns? In fact,ns is not the best at such problems.
•  » » » 3 years ago, # ^ | ← Rev. 2 →   +116 As a tester, just joking.In fact, I think the problems are okay as a codeforces round.But in China, lxl (ODT 's Chinese name) is considered as a problem setter of the most difficult and troublesome problems.And many contestants are afraid of lxl, and always think that his problems are bad. I just want to say that, the contest is quite good, and lxl and the others authors work very hard to make a good contest!Wish you have fun in the contest!See you all!
•  » » » » 3 years ago, # ^ |   +34 Chinese CodeForces div1 rounds' difficulty is above average anyways Nope Nope Nope Nobody's gonna AK this Chinese round.jpg
•  » » » » 3 years ago, # ^ |   0 Chinese CodeForces div1 rounds usually have less hacks， so I dislike them.
 » 3 years ago, # | ← Rev. 2 →   +31 Why it isn't in the main page? UPD: It's now :D
 » 3 years ago, # |   +24 Chtholly is good!
 » 3 years ago, # |   +33 The happiest girl in the world!
 » 3 years ago, # |   +55 Wish everyone enjoys the round and few bugs! And hope all the programs will be fast in practice :D
 » 3 years ago, # |   +30 Chtholly is invading Codeforces... And, I really don't want a math contest! PLS!
•  » » 3 years ago, # ^ |   +41 It surely won't be a math contest. It might be a Data Structure contest, I suppose.
 » 3 years ago, # |   +47 No tricks please
•  » » 3 years ago, # ^ |   +2 Where can I find these pictures?They are very interesting!
 » 3 years ago, # |   0 Auto comment: topic has been updated by ODT (previous revision, new revision, compare).
 » 3 years ago, # |   0 Auto comment: topic has been updated by ODT (previous revision, new revision, compare).
 » 3 years ago, # |   0 ke jiao xing guo(
 » 3 years ago, # | ← Rev. 2 →   +54
•  » » 3 years ago, # ^ |   +16 The girl on the picture is not Chtholly :(
 » 3 years ago, # |   +54 Interactive Guide — Div 2 I am comming back :D
 » 3 years ago, # |   +30 Hope not to meet five data structure problems...
•  » » 3 years ago, # ^ |   +15 Hope not to meet five data structure problems, too.
•  » » » 3 years ago, # ^ | ← Rev. 2 →   +9 Hope not to meet five problems with block dividing algorithm, too.
 » 3 years ago, # |   +76 Data Structures Round? Very interesting! But I hope there will be less data structures problem. :)
•  » » 3 years ago, # ^ |   +6 I know you are good at solving data structure problems! Aren't you?
•  » » » 3 years ago, # ^ |   +41 I agree with you.
•  » » 3 years ago, # ^ |   0 YYQ AK!
•  » » 3 years ago, # ^ |   0 YYQ AK!
•  » » 3 years ago, # ^ |   -18 YYQ AK!
 » 3 years ago, # |   -35 I can't read the annoucement again...
•  » » 3 years ago, # ^ |   +3 Check your internet connection! XD
•  » » » 3 years ago, # ^ |   0 I mean,I have no bravery to read it again:(
 » 3 years ago, # |   +18 Is Chtholly rated?
 » 3 years ago, # |   +8 Dear ODT, why not to darw chtholly with me? It will be fun, my dear friend!
•  » » 3 years ago, # ^ |   -39 What is "darw"??? Is it English?
 » 3 years ago, # | ← Rev. 5 →   -107 Some interesting IDs belonging to ODT upvote this annoucement...But I prefer to practice FalunDafa rather than take part in this round! В конце концов, Чжэнь Шань Жэнь это единственный критерий для оценки хорошего или плохого человека.
 » 3 years ago, # |   0 Chtholly is good! hope the contest will be the same as usual. also hope everyone high rating!
 » 3 years ago, # |   -9 Could you resize the image to be a bit smaller? It looks really weird on the front page.
•  » » 3 years ago, # ^ |   -47 I think your avatar is pretty weird!
 » 3 years ago, # | ← Rev. 4 →   +62 DULIU mcfx HENTAI lxl I will never participate in a DS round! (emmm... and I advise ODT to prepare for National Higher Education Entrance Examination in a hurry (wu
•  » » 3 years ago, # ^ |   +32 lxl :I can pass the exam easily and taking lessons does nothing to me!So I will make more DULIU problems to make money!(:
 » 3 years ago, # | ← Rev. 8 →   +3 Chtholly Nota Seniorious! orz krydom ,upstairs ↑.Chtholly Nota Seniorious こんなにも、たくさんの幸せをあの人に分けてもらった だから、きっと 今の、私は 谁が何と言おうと 世界一、幸せな女の子だ I think this contest will be very interesting!But "Is Chtholly rated?"
 » 3 years ago, # |   -20 another weeaboo garbage jesus fuckign christ what happened to this website
•  » » 3 years ago, # ^ |   -42 No, we practice Falun Dafa, we are real and kind and forbearing.
•  » » » 3 years ago, # ^ |   0 The police is coming for you.
•  » » » » 3 years ago, # ^ |   -21 Let them come. A real Falun Dafa studier is not afraid of commies.
•  » » » » » 3 years ago, # ^ |   0 I guess you'd better shut your f**k**g Falun mouth before you attract more police to our computer room.
•  » » » » » » 3 years ago, # ^ |   -8 You d***less person get away
•  » » » » » » » 3 years ago, # ^ |   0 Don't be so rude, my friend :)
•  » » » » » » » » 3 years ago, # ^ |   -10 Yes, at least we are all anti-commies.
 » 3 years ago, # | ← Rev. 9 →   +26 zcy!!! is he the man who has hung and beaten the trained team ? %%%%I like this round of contest
•  » » 3 years ago, # ^ |   0 That's lxl!
 » 3 years ago, # | ← Rev. 3 →   +3 I think too many big images and words in animes appearing in the contest will make me feel #%#\$@^(&#! when I solve problems.I hate people who put big image of Chtholly everywhere!死宅真恶心
•  » » 3 years ago, # ^ |   +18 Not so big. KAN will sure that the image in a small size :(
 » 3 years ago, # | ← Rev. 3 →   +15 ODT YOU NOT YELLOW MATE
•  » » 3 years ago, # ^ |   +12 Does that mean he can't be a good problem setter?By the way, ODT is very excellent!
 » 3 years ago, # |   +5 Love this Anime and LN so much :> Hope everyone high rating and have fun coding :>
 » 3 years ago, # | ← Rev. 2 →   -6 Looking forward to such a 'colourful' contest! Well, except troublesome Data Structures. Uh, I'm wondering if there will be big pictures in desciptions of problems.
•  » » 3 years ago, # ^ |   0 This picture is really nice. I wonder where do you find it.
•  » » » 3 years ago, # ^ |   0 this picture is famous, dont't you know? Use baidu before asking! ( www.chtholly.ac.cn is also a nice choice!) :)
•  » » » » 3 years ago, # ^ |   +5 well, I didn't find the picture above on baidu indeed.
•  » » 3 years ago, # ^ |   0 cyand1317 confirmed there won't. Thanks cyand.
•  » » » 3 years ago, # ^ |   0 So after consideration and discussion, we've reached this decision.There won't be large, distracting images. Some problems contain smaller images that may act as a delimiter, though — start reading the statements after the image if you'd like to.
•  » » » » 3 years ago, # ^ |   0 I agree it's the best decision about images in problems. I'd like some lovely images and decriptions or scripts about animes, though. Therefore, I can decide if I'm interested in that anime and whether to see it later. However, many feel sick about images of cartoons. I suppose this is the best balance, making ODT able to share and express, while not disgusting others. Anyway, lxl just can't help putting his beloved into problems.
•  » » » » » 3 years ago, # ^ |   0 Wanna know if you'd like that anime? Go to MAL, not cf.I like some anime, but I don't want it mixed into problems. It's like saying, "wow I like soda, gonna make some soda-flavored pasta :D"
 » 3 years ago, # |   -41 Again these shitty anime pictures covering the whole screen...
 » 3 years ago, # | ← Rev. 4 →   +8 Yet another anime round,but with DULIU problem setters...But cheerful with Chtholly :)
 » 3 years ago, # |   -46 I think its not good to use Interactive Problem because many Div. 2 contestants. dont know it for me i didn't see it before
•  » » 3 years ago, # ^ |   +46 So why don't you go through the interactive problems guide as suggested in the blog?
•  » » » 3 years ago, # ^ |   -28 I did but i suggest it will be good to use it in educational round or unrated one
•  » » » » 3 years ago, # ^ |   +57 This might be harsh — but you are not going to solve anything and improve with this attitude.
•  » » » » » 3 years ago, # ^ |   -24 So what is your suggestion ?
•  » » » » » » 3 years ago, # ^ | ← Rev. 2 →   +23 Solve an old interactive problem if you don't feel confident.
 » 3 years ago, # |   -15 I love these anime rounds :D
 » 3 years ago, # |   -23 I also like animes
 » 3 years ago, # |   -11 Wow anime round ! what could be better!
 » 3 years ago, # |   0 Wish round will be without system errors! And of course, wish problems will interesting and enjoyable ...) Wish everybody high rating and good mood for night after contest!
 » 3 years ago, # |   0 lxl(aka. nzhtl1477, ODT) is really a toxic tumor!
 » 3 years ago, # |   +71 Oh look, another anime that every weeb have watched it except me. Somehow people really like to recommend this anime but I am so triggered by it's title so I skipped it because of it's title is literally longer than my cumbersome comment.PS: Weebs are taking over ICPC in EC in case if you don't know(full login password: I love Megumi, Google Megumi Kato)
•  » » 3 years ago, # ^ | ← Rev. 3 →   +6 Pffft, Megumi from konosuba is wayyyy cuter. EDIT: Oops, this is Megumin not Megumi. Sorry.
•  » » » 3 years ago, # ^ |   +28 Except this is Megumin.
•  » » » » 3 years ago, # ^ |   +13 'n' is often added to Japanese names to make them cuter.Which means megumin is cuter than megumi >:D
 » 3 years ago, # |   0 Hope everyone will have fun with Chtholly in this round~ P.S. I love Nephren forever!
•  » » 3 years ago, # ^ |   0 When there will be a "Nephren Round"?
 » 3 years ago, # | ← Rev. 2 →   +33 I like this contest! Maybe I'll participate in it.
•  » » 3 years ago, # ^ |   +2 Maybe Chtholly will get high rank in Chtholly round
•  » » » 3 years ago, # ^ |   0 Not maybe, It should be: "must be" :P
•  » » 3 years ago, # ^ |   0 You did it and done great ... congrats !!
 » 3 years ago, # |   +25 The amount of discussion on this thread is growing faster than exponential running time! :O
 » 3 years ago, # |   0 Yeee, anime round, we all were missing it.
 » 3 years ago, # |   0 An anime round?Or a lxl data structure round?
•  » » 3 years ago, # ^ | ← Rev. 2 →   +6 This won't be a lxl data structure round.
 » 3 years ago, # |   -8 glhf
 » 3 years ago, # |   -6 On one hand, data structure problems are nice, but on the other hand, we have interactive...
 » 3 years ago, # |   +8 Hope the network is good tomorrow. The server was down for several times this week.
 » 3 years ago, # |   +40 How to solve D? I used binary search + FFT but it was TLE.
•  » » 3 years ago, # ^ |   +43 You need to use online dynamic persistent red-black tree with square root decomposition + some dp optimizaton + FFT
•  » » 3 years ago, # ^ | ← Rev. 2 →   +32 Thanks a lot. I finally figured out the TLE test case of my solution: 5 1 -4 1 3 4 5 3 1 2 2 4 7 
 » 3 years ago, # |   +9 But seriously, why most of light novel need to have a ridiculously long title? This, Moshidora and Oreimo each seems like they have about 50++ characters in their title >_<
•  » » 3 years ago, # ^ |   0 So 51 characters?
•  » » » 3 years ago, # ^ |   0 nah it returns 50.
•  » » » » 3 years ago, # ^ |   0 you were right
 » 3 years ago, # |   -9 V I R A JM A D D U R
•  » » 3 years ago, # ^ |   0 WeEEeeeEeeEeEEEbs
•  » » » 3 years ago, # ^ |   +28
 » 3 years ago, # | ← Rev. 2 →   0 It seems to be an unsolvable round?Five difficult data structure problems!
 » 3 years ago, # |   -13 这这这……what is this? 好像混进了什么东西。
 » 3 years ago, # |   +34 How to solve Div1 A? I code for 10KB but got WA.
•  » » 3 years ago, # ^ |   +23 You only code for 10KB? How could you do that?
•  » » 3 years ago, # ^ |   +17 What? How can you solve it within a 10Kb-code? I have code 30Kb but I haven't finished it yet! :(
•  » » 3 years ago, # ^ | ← Rev. 3 →   +12 What makes you sure that you can solve it within a 10kb code,bro?
•  » » » 3 years ago, # ^ |   +16 Beacuse I think it's Div1 A, so I think the code won't be too long.
•  » » » » 3 years ago, # ^ |   +8 Have you forgotten who are the editors of this round? XD
•  » » » » 3 years ago, # ^ |   +12 Wake up mate, it's ODT's problem, the code can't be short.
•  » » » » » 3 years ago, # ^ |   +9 Oh.. I forgot the editors of this round! thx bro, I will recode soon! :)
•  » » 3 years ago, # ^ |   +15 But I wrote a 5KB code and got accepted :)
•  » » » 3 years ago, # ^ |   +3 You are so strong :) I have just complete it in 35Kb. (QAQ)
•  » » » » 3 years ago, # ^ | ← Rev. 2 →   +8 In fact, I missed a 0. So it is 50KB :)
•  » » » » » 3 years ago, # ^ |   0 But you got AC.
•  » » » » » » 3 years ago, # ^ |   +6 I got WA199 at last :(
•  » » » » 3 years ago, # ^ |   +2 I lose hope on recoding :( It's too long..
•  » » » » » 3 years ago, # ^ |   +1 Why not try to get the answers with a Brute force and just print the answers for each tasks? Certainly you need to beg others in your room not to hack you XD
•  » » » » » » 3 years ago, # ^ |   +1 An FST will be ready for you :) You know, those problem setters are hackers :)
•  » » » » » » » 3 years ago, # ^ |   0 Oh no I hope that setters are lazy and just made weak data,though I'm sure that is impossible. :(
•  » » » » » » 3 years ago, # ^ | ← Rev. 2 →   0 You can submit it at the last second so that no one can hack you.
•  » » » » » » » 3 years ago, # ^ |   0 Oops, Problem setters can :)
•  » » 3 years ago, # ^ |   +5 I got accepted and the time complexity is only O(logn) !
 » 3 years ago, # |   +14 How to solve Div.1 F? It's a challenging problem with a 30s time limit. :(
•  » » 3 years ago, # ^ |   +20 Wake up bro, the article has said : This round has 5 problems in each division and you have 2 hours to solve them. No problem F in Div1 :)
•  » » » 3 years ago, # ^ |   +16 I know that :) So why is there an F? emmmmmmmmm maybe a DULIU problem setter?
•  » » » » 3 years ago, # ^ |   0 Maybe an extra problem. So you can imagine how difficult it is...
•  » » » » 3 years ago, # ^ |   +10 What means 'DULIU'?
•  » » » » » 3 years ago, # ^ | ← Rev. 4 →   +29 There are many kinds of DULIU problems,such as: The author's solution runs 0.9s,and the time limit is 1s. The author uses 5 hours to write the solution and the length of the contest is 3 hours. The author uses some strange algorithms to solve the problem.
•  » » » » » 3 years ago, # ^ |   0 DULIU (毒瘤) means tumor in Chinese
•  » » » » » 3 years ago, # ^ |   0 It refers to those problem setters who set up exceedingly difficult and troublesome problems, thus making most problem solvers revolted so that they can't help complaining that the problems and their setter are really DULIU.
•  » » » 3 years ago, # ^ | ← Rev. 2 →   +11 If you can solve all the problems and the total length of the codes is less than 50kb,you can see the Div.1 F.
 » 3 years ago, # |   0 How to sovle Div1C with block dividing algorithm? I got TLE over and over again.
•  » » 3 years ago, # ^ |   +2 use std::bitset` and do some constant optimizations.
 » 3 years ago, # |   +12 Observe in the dark
 » 3 years ago, # | ← Rev. 2 →   +4 Deleted
 » 3 years ago, # |   +39 Let's wish Good Luck codeforces servers)
 » 3 years ago, # |   +27 CONTEST: Omae wa mou shindeiru!ME: NANI?
 » 3 years ago, # |   +1 What's up with this weird discussion going on? Is ODT bad problem setter? Can you guys link me to some of his contests? This is really interesting.
•  » » 3 years ago, # ^ |   0
 » 3 years ago, # |   -9 if u r a true anime fan u should watch boku no pico great anime with intresting plot
•  » » 3 years ago, # ^ |   0 yoooooooooooooooooo I'd NEVER watch that! It's revolting. I'd like lovely Chtholly better.
•  » » » 3 years ago, # ^ |   0 u should give it a try
•  » » 3 years ago, # ^ |   0 I can confirm this is true, I've watched that many time before. 10/10 would watch again though.P.s: Pico best girl.
 » 3 years ago, # |   +34 Every 3rd round on codeforces since I have joined is unrated due to some tech issues. I am scared today :p
•  » » 3 years ago, # ^ |   0 The queue is insane.
 » 3 years ago, # |   +47 Long queue for anyone else?
•  » » 3 years ago, # ^ |   +3 yes!
•  » » 3 years ago, # ^ |   0 I just waited for an hour and got a WA.
 » 3 years ago, # |   +2 welp, guess i'm doing something else of my afternoon than a codeforces round...
 » 3 years ago, # |   0 Lol this will probably be unrated
 » 3 years ago, # |   0 I see where the contest is going.
 » 3 years ago, # | ← Rev. 2 →   +2 6-minute-queuing (until the moment I write this comment). Last time I started to complain about queuing issue, it subsided a few minutes later. Hope it will work this time as well :<
•  » » 3 years ago, # ^ |   +7 I've submitted a code with 22 minutes. No response yet. So, I it's a 16min+ queue time.
•  » » » 3 years ago, # ^ |   0 Well this is starting to get ugly...
 » 3 years ago, # |   -11 trash contest with anime garbage and shit servers as always gj codeforces
 » 3 years ago, # |   +3 30+ pages of queue? How is anyone supposed to time manage like this :/
•  » » 3 years ago, # ^ | ← Rev. 2 →   +27 My submissions can't even pass "pretest 1", because they TLE on "in queue"
 » 3 years ago, # |   +13 37 pages queue...
•  » » 3 years ago, # ^ |   +18
 » 3 years ago, # |   +2 No server problems so far but the queue is just as bad!
 » 3 years ago, # |   +2 In queue = unrated pls
 » 3 years ago, # |   +8 Long queue. Submitted B 20 minutes ago and still no verdict
 » 3 years ago, # |   0 Submitted B 20 minutes ago and only now I get a response that I missed it. This is pretty unfair and I request it becomes unrated.
•  » » 3 years ago, # ^ |   0 time to wait another 20 minutes to see if I got it
 » 3 years ago, # | ← Rev. 2 →   +18
 » 3 years ago, # |   +56
 » 3 years ago, # |   +14 The math says system testing will finish before pretest :-P
 » 3 years ago, # | ← Rev. 2 →   +8 Seems fair that chtholly might win the contest
 » 3 years ago, # |   +15 nearly 40 pages queue, should I continue the contest or not? :P
 » 3 years ago, # |   0 I'll go watch WorldEnd while waiting for the queue .__.
 » 3 years ago, # |   +11 The nice problemset was simply ruined because of the queue :/
 » 3 years ago, # |   +14 Unrated
 » 3 years ago, # |   +3 Unrated again ?
 » 3 years ago, # |   +11 Maybe unrated Sad :(
 » 3 years ago, # |   +59 What are you doing at the beginning of codeforces round449？ Are the judger busy？Will it judge our submissions of this contest？
 » 3 years ago, # |   +24 After 40 minutes I got my verdict Wrong Answer ! And after re-submitting when I will get my verdict ? After the contest ends?
 » 3 years ago, # |   0 I submitted 1st question in 9 min and got a score of 488 and after 2 min it was reduced to 428. Can anyone explain why? All the pretests passed and the total score was still 470 and yet they gave me 428?
•  » » 3 years ago, # ^ |   -7 MikeMirzayanov Please look into it. I do not understand how someone can score less marks then the maximum marks at that instant even after passing all the pretests. I got 488 and then it was changed to 428. but why?
•  » » 3 years ago, # ^ |   +5 Your solution got submitted twice. Even if pretests on the first submission pass, it is counted as 1 penalty.
•  » » » 3 years ago, # ^ |   0 Isn't it awkward? I have never faced any such problem in previous contests. Are the rules different in this round?
•  » » » » 3 years ago, # ^ |   0 it's already mentioned in rules.check score table more details
 » 3 years ago, # | ← Rev. 2 →   0 I won't save a poisonous problem setter even if I'm not busy at all ：（
 » 3 years ago, # |   +53 Dear codeforces, please hire some good engineers . those who can manage your servers
 » 3 years ago, # |   +141 Did you know that 55 is not only the fifth palindrome number with 2 digits, but it is also THE NUMBER OF PAGES IN THE QUEUE?
•  » » 3 years ago, # ^ |   +13
 » 3 years ago, # |   +68
 » 3 years ago, # |   +42 I just waited 30 minutes to find wrong answer verdict
 » 3 years ago, # |   +109
 » 3 years ago, # |   +43
•  » » 3 years ago, # ^ |   0 momentum conservation law? Interesting.
 » 3 years ago, # |   0 My rating is going to increase !! So it is only fair that the round gets unrated.
 » 3 years ago, # | ← Rev. 4 →   +17 Oh this is just great. (35 minutes waiting for that verdict) And also this one. "Working on"? — I guess it should be an unrated announcement instead... UPD: Seemed like many people's opinions are going to the void.
 » 3 years ago, # |   +114 Waiting for round getting declared unrated and Mike's apology blog
•  » » 3 years ago, # ^ |   0 SAVAGE
•  » » » 3 years ago, # ^ |   0 :)
 » 3 years ago, # |   0 Was testing system replaced by a group of Chinese? :)Btw, problems are very good.
•  » » 3 years ago, # ^ |   +4 problems was good ? oh man are you kidding ? problem C / Div2 , A / Div 1 was good and beautiful ?
•  » » » 3 years ago, # ^ |   0 Not beautiful, but good. B and C are better than A(div1). It's just my opinion.
•  » » 3 years ago, # ^ |   -21 You are racist.
 » 3 years ago, # | ← Rev. 4 →   +82 I got a friendly advice to make a standalone blog instead, but couldn't delete the original message, because it was too old.
 » 3 years ago, # |   +35 I think we will need BigInteger queue, because long queue will overflow :'D
 » 3 years ago, # |   +8 It seems to be unrated :(...So sad to hear about it...
 » 3 years ago, # |   +107
 » 3 years ago, # |   +19 The announcement should be "This contest is unrated!"
 » 3 years ago, # |   +6 I have lost hope to solve the problem. Because of [unsigned long long] queue and the HARD problem(Div.1) :(But, it seems to be unrated?
 » 3 years ago, # |   +16 And here's another unrated contest -_-
 » 3 years ago, # |   +13 The girl in the post is shedding tears because of the loooooooong queue...
•  » » 3 years ago, # ^ |   +3 Steelix used unrated attack It was super effective! Togekiss fainted!
 » 3 years ago, # |   +12 i think that the end of the queue is at the end of the world...
 » 3 years ago, # | ← Rev. 3 →   +11 Unrated please; the server problems this contest are much, much worse than last contest, and the last contest was unrated, so this one should be too.
 » 3 years ago, # |   +7 It's not the first time such long queues on Codeforces, it's time to buy normal servers. And yes, the round should have been unrated
 » 3 years ago, # |   0 nearly 50 pages queue
 » 3 years ago, # |   +70 Dear Mike Mirzayanov,I think it's time to announce this round unrated because of failing to fix the issue with the judging machine. It's 11-12 pm in some time zone and it's time to sleep if the contest is declared unrated. Thank you for understanding us. Best wishes.
 » 3 years ago, # |   +18 Please unrate it.Getting W/A after waiting for 35 mins straight is just so frustrating.
 » 3 years ago, # |   +31 What are you doing at the end of the queue? Are you busy? Will you test us?
 » 3 years ago, # |   +12 This is my second codeforces round! And I will be unrated until 2018 =)
 » 3 years ago, # |   +24
 » 3 years ago, # |   +1 And you knew that the length of the last line in task C, is equal to the NUMBER OF ASSIGMENTS IN THE QUEUE!!!!!
 » 3 years ago, # | ← Rev. 2 →   +1 That wonderful feeling when you submitted your solution about 50 minutes ago and now it gets RE 7. Love Codeforces servers!)
 » 3 years ago, # |   +30 Round extended by 15 minutes? Do you think this will make the round any better?
•  » » 3 years ago, # ^ |   +13 Maybe he just want to get 15 more minutes to consider whether making this round unrated due to technical problems. :D
 » 3 years ago, # |   +6 Increase the time by merely 15 min and decrease the score like a landslide? I don't think 15 min is enough though ! This has to be unrated !!!
 » 3 years ago, # |   0 And after all this they extend the contest by 15 minutes!!! Do they still expect to make it rated??? I don't know whether to laugh or cry!!! That's damn funny!
 » 3 years ago, # |   0 In Educational Codeforces Round 33 (Rated for Div. 2) , I waited for the long queue but that round was still rated.
•  » » 3 years ago, # ^ |   +2 The queue in that contest was at most 10 minutes (I think), which I feel is STILL fine, compared to today (It's not ideal, but it's manageable). Today, people had to wait for 30-40 minutes to receive a verdict.
 » 3 years ago, # |   +6 Lagforces round #449
 » 3 years ago, # |   +59 I will leave CF if this round is rated.
•  » » 3 years ago, # ^ | ← Rev. 2 →   +5 Still in long queue!! RIP CF
•  » » 3 years ago, # ^ |   0 genuine question: What will you do now since the round is semi-rated ?
•  » » » 3 years ago, # ^ | ← Rev. 2 →   0 My rating has been changed, so I leave CF.
 » 3 years ago, # |   +69
 » 3 years ago, # |   +8 What are we going to do in 15 minutes if verdict is given after 40 minutes? -_-
 » 3 years ago, # |   +33 When you are Codeforces, and have a 40+ page queue
 » 3 years ago, # |   +250 :')
 » 3 years ago, # |   +10 It won't be a surprise if the comments on this thread are also queued LOL!
 » 3 years ago, # |   +5 Waited for 25 minutes & got WA
 » 3 years ago, # |   +28 we could use this waiting time for Hacking. _/_ Codeforces.
 » 3 years ago, # |   0 too hard problems for me
 » 3 years ago, # |   +18 What do you do at the end of the World? Are you busy? Will you save Codeforces?
 » 3 years ago, # |   +10 damn that problem C, I know I did something wrong,but the problem feels really frustrating, like hardcoding,my eyes hurt after reading that statement "will you save us...." also was waiting long long time before verditc came "wrong answer on pretest 5" like , FUCK NO,not attempting that again after 30 minutes :(
•  » » 3 years ago, # ^ |   +9 Make it unrated...!!
 » 3 years ago, # |   +95
 » 3 years ago, # |   -10 The problems are very good . thanks to the writers . but long queue :(
 » 3 years ago, # |   0 Meanwhile CODEFORCES !:D xD D
 » 3 years ago, # |   +114 Dear "whoever decided to extend contest by 15 minutes", Do you really think that additional 15 minutes would make this competition fair? Or it is just some desperate attempt to make this contest rated? If it's the first case: - no competition would be far from fair, I've been waiting about half an hour to see that my program does not work. Then I tried to fix something... guess what — I've been waiting another half an hour to see that a bug I found was not the only one. The point is — I should know what I know now max 10 minutes after my first submission (and it was 60, where are my 50 minutes?). My first concern is about amount of additional time. Why 15 minutes seems to be enough to make this contest fair? I don't feel like this is enough. The second thing is what ranking should be — is a person who get accept after X minutes at first try better or worse than person which would get accept after several trials in the first Y minutes (especially for X >> Y)? Because long testing queues affect the second one, but not the first one.If it's the second case: please don't — just admit that it did not work out, that's what adult people do.Sincerely, Kroma
•  » » 3 years ago, # ^ | ← Rev. 2 →   +8 I agree with you, but extending the round doesn't mean they are going to make it rated. I am saying this because, in a very recent contest, there was an extension of 30 minutes (!), but the contest was still declared unrated (for the same reason as today).
•  » » » 3 years ago, # ^ |   -8 Yeah, and the server was faster that day than today ;)
•  » » » 3 years ago, # ^ |   0 If that's the case, then I'm sorry that I exposed you to my butthurt. To explain myself I can only say that I would bother with extending time iff there is a chance to make it rated. So I assumed that "whoever decided to extend contest by 15 minutes" may have similar approach.
 » 3 years ago, # | ← Rev. 2 →   +1 The queue has disappeared... I don't know whether it's a good news or a bad one. Does it mean that the round will be rated? What a sad story... But I do think that a lot of contestants have go to bed after seeing the extremely long queue one or half an hour after the contest began. So do you think it is fair to make it rated?
 » 3 years ago, # | ← Rev. 3 →   +7 Although the queues have been cleared but please declare the round as unrated, 1. Some of us waited for long just to get a wrong answer. 2. Many of us lost the hope to continue the contest and hence going by the past trends we already assumed that it's gonna get unrated.
 » 3 years ago, # |   +23 After only 40 minutes waiting only 15 minutes ???
 » 3 years ago, # |   0 I submitted 2 solutions to problem 1 , in 9 min and in 11 min. Both got accepted and I got a penalty as well. Is it normal in codeforces or there is some malfunctioning going on? Initially I got 488 score and after 2 min it was reduced to 428. Sad :( MikeMirzayanov
•  » » 3 years ago, # ^ |   +11 there's a 50 point penalty for resubmission
•  » » 3 years ago, # ^ |   +9 It's normal. There's a 50 point penalty for resubmission regardless of the correctness of the previous submission.
•  » » » 3 years ago, # ^ |   0 OK :(
 » 3 years ago, # |   0 div.2 a,b aren't good for hackers......
 » 3 years ago, # |   +29 This has to be unrated... many people have lost 30+ minutes because they got WA after a super long queue.
•  » » 3 years ago, # ^ |   +4 What's worse is that resubmitting needs another 30 minutes to get another WA on the same test case. :(
 » 3 years ago, # |   +5 Queue lag + Server lag = Unrated pls?I even lagged out while trying to post this lol.
 » 3 years ago, # |   +19 I really wonder why CF is not being open sourced ??(it's not a profit making site, right ?) .The website suffers every other round, I'm sure are many people willing to help CF.
 » 3 years ago, # |   -57 Your contest is very stupid please don't repeat this awful... Your problems are unprofessional.
•  » » 3 years ago, # ^ | ← Rev. 2 →   +31 :| why unprofessional ?if you cant solve them it's not their fault!
•  » » 3 years ago, # ^ |   0 And what is a "professional" problem? I know these problems could be improved, but the big issue about this contest was the long queue
 » 3 years ago, # |   -37 MikeMirzayanov Make it rated please ^^
 » 3 years ago, # |   +36 I hope that this round won't be rated. I waited for the result for half an hour,then the Web told me that I was wrong, then I used 1 minute to fixed the bug .But it didn't work again,and I waited for another half an hour. So I used 3600 seconds to fix a bug .Time is money.We shouldn't waste our time. I'm Chinese student ,I have so much homework to do. I tried my best to save time to do the round .If the round will be rated ,not only me ,but also many other people will get very angry. (My English is not good ,I just tried my best to explain my opinion)
•  » » 3 years ago, # ^ |   +9 Agree with you
 » 3 years ago, # | ← Rev. 2 →   +27 When almost everyone asking for an unrated round has performed poorly
 » 3 years ago, # |   +50 I don't know what's worse: The long queues in every other round of CodeForces or the way CodeForces handles these rounds (Extending the round and keeping the participants in the dark about the contest being rated/unrated, and finally making it unrated after the contest ends — A desperate attempt to ensure that the participants take part in the contest and do not leave it midway).
•  » » 3 years ago, # ^ |   0 You nailed it! Instead of stopping confusion as soon as possible they prolong it even further.
 » 3 years ago, # |   +11 What are you doing at the end of the queue? Are you busy? Will you test us?
 » 3 years ago, # |   +8 Good problems but awful contest.
 » 3 years ago, # |   +6 what is test 5 for C ?!
 » 3 years ago, # |   +15 D is just https://en.wikipedia.org/wiki/Catalan%27s_triangle + compute binomial for arbitrary modulo.
•  » » 3 years ago, # ^ |   +11 "How do we make this question harder?""Make it modulo anything instead of 1e9+7"Always work with a charm. (**Smacks my own face for not keeping another combinational template**)
•  » » 3 years ago, # ^ |   0 But how do you handle sum from l to r(and C-type customers)?
•  » » » 3 years ago, # ^ |   +10 Fix the number of paying. Sum from l to r is reduced into two binomial terms.
 » 3 years ago, # | ← Rev. 2 →   0 Div 1. A. I wrote a program that kept on failing pretest 1 even though it worked on my computer. What ended up fixing it was doing my preprocessing before reading the input, which should not have changed anything. This issue took me one hour to catch since it took a good 30 minutes for the test results to get back and another 30 minutes for me to figure it out.
 » 3 years ago, # | ← Rev. 2 →   +4 How to solve C and E?On E I had a solution which didn't pass. Did someone pass it with such complexity? Also is there a way to solve it without SQRT decomposition?PS: I think the round should definitely be unrated, because with such a queue it's not worth looking at the easy problems (Div. 1 A and B) as you may do a stupid bug and then be punished really hard. And so a lot of people start solving the harder problems and the chance of them failing the competition increases (for example I did so — I didn't even read B). Also a lot of people probably gave up after seeing such a queue. PS2: The people which passed E all have the solution. The constant of my solution should really be large xD
•  » » 3 years ago, # ^ |   +5 On C operations are random and the queries don't depend on the order of numbers so expect a lot of adjacent numbers to be equal...
•  » » 3 years ago, # ^ |   0 msqrt(n)logn + nlog^2n algorithm using binary search tree?
•  » » » 3 years ago, # ^ |   0 yep (treap)
•  » » » » 3 years ago, # ^ |   0 The constant of this algorithm is too big... You can optimize it into O( msqrt( nlogn ) + nlog^2n ), but I think it still wont pass.
 » 3 years ago, # |   0 for n=1; this is the string "What are you doing while sending What are you doing at the end of the world? Are you busy? Will you save us?? Are you busy? Will you send What are you doing at the end of the world? Are you busy? Will you save us??" and in this string the 194th char is 'y' but in the given test case it is 'b'! please help me if i have build the string in the wrong way please guide me!
•  » » 3 years ago, # ^ |   0 You are missing the quotation marks when you reffer to "f(i-1)"
•  » » 3 years ago, # ^ |   0 You missed including the quote " right before and after the nested string.
•  » » 3 years ago, # ^ | ← Rev. 2 →   0 The 194th char is 'b'. There are 218 characters in string f1, so if you start counting backwards from the last character you'll end up at 'b' in 'busy' on char 194. Make sure to count spaces and punctuation as well. Edit: I think putting in quotations will fix the problem.
 » 3 years ago, # |   0 Is D all about Catalan number + DP? I regret ignoring an algorithm which computes (nCi mod non-prime for all i) in O(n) time. :/
 » 3 years ago, # |   +3 There is no argument defending that the round should be rated. Please make it unrated as it has affected many of the participants badly.
•  » » 3 years ago, # ^ |   0 I know I M newbie and my opinions do not matter but still I am talking complete sense and this round should be unrated.
 » 3 years ago, # |   +25 Unrated please dude
 » 3 years ago, # |   0 how to solve div2 B
•  » » 3 years ago, # ^ |   +3 i th number is of format ireverse(i) for example 10th number is 1001
•  » » » 3 years ago, # ^ |   0 .................... I'm so stupid.......
•  » » » » 3 years ago, # ^ |   0 ME to realized tooooooooooooooooo late
•  » » 3 years ago, # ^ |   0 I tried to generate all this "zcy" numbers, but still got WA 3 )) http://codeforces.com/contest/897/submission/32875222
•  » » 3 years ago, # ^ |   0 "zcy number" is actually just a positive number, followed by its mirror.(Like "153351" is just "153" and its mirror — "351")So you can iterate from 1 to k, generate the zcy number and add its value. Remember the modulo.
•  » » » 3 years ago, # ^ |   0 Wow, I think this is such a clever idea!! I did not notice this during the contest...Instead, I used another method to generate the first 100000+10 zcy numbers, and calculate their sum.
•  » » 3 years ago, # ^ |   0 although final test cases havent run on my solution , here's my idea. nth such number will be write down n then invert it and join to form the number.Just take the sum and keep moulp.Happy coding:)
 » 3 years ago, # |   +4 when in queue ( but expecting correct answer ) : PLEASE MAKE IT RATED after getting WA : PLEASE MAKE IT UNRATEDafter mains when everyone gets WA : PLEASE MAKE IT RATED
•  » » 3 years ago, # ^ |   0 bro tell me
 » 3 years ago, # | ← Rev. 4 →   +19 It would really be unfair to rate this round because many of us solved the problems faster than our submission times show; many of us submit, wait for a very long time, and find out our submission was incorrect, resulting in us losing more time than we should have. Today, the time lost was significant; some people lost up to 1 hour waiting for submissions. Personally, I lost a total of about 1 hour of time just waiting for the result of my submission (you don't know whether to continue working on a problem or not until you see the verdict), and I'm sure that many other people are in the same situation as me. In addition, Codeforces Round 445, which happened a few weeks ago, featured servers that were awfully slow, yet still faster than today's. Given that it was still unrated, today's contest should also be unrated.
•  » » 3 years ago, # ^ |   +23 I got compilation error after waiting for 30 minutes lol
 » 3 y