### Stepavly's blog

By Stepavly, history, 16 months ago, translation,

Hello, Codeforces!

<almost-copy-pasted-part>

Hello! Codeforces Round #650 (Div. 3) will start at Jun/16/2020 17:35 (Moscow time). You will be offered 6 problems (one of them will have subtasks) with expected difficulties to compose an interesting competition for participants with ratings up to 1600. However, all of you who wish to take part and have a rating 1600 or higher, can register for the round unofficially. The round will be hosted by rules of educational rounds (extended ACM-ICPC). Thus, during the round, solutions will be judged on preliminary tests, and after the round it will be a 12-hour phase of open hacks. We tried to make strong tests — just like you will be upset if many solutions fail after the contest is over.

You will be given 6 problems and 2 hours to solve them.

Note that the penalty for the wrong submission in this round (and the following Div. 3 rounds) is 10 minutes.

Remember that only the trusted participants of the third division will be included in the official standings table. As it is written by link, this is a compulsory measure for combating unsporting behavior. To qualify as trusted participants of the third division, you must:

• take part in at least two rated rounds (and solve at least one problem in each of them),
• do not have a point of 1900 or higher in the rating.

Regardless of whether you are a trusted participant of the third division or not, if your rating is less than 1600, then the round will be rated for you.

The problems for this round were invented by MikeMirzayanov, me and Supermagzzz and prepared by me and Supermagzzz.

Thanks to MikeMirzayanov for platforms and coordination of our work. Thanks to harlequen, manta1130, lynmisakura, Gassa, Rox, antontrygubO_o, armoking, JustasLe, iankury, Sho, bugdone, Khairy for help in round preparation and testing the round.

Good luck!

Editorial

</almost-copy-pasted-part>

• +384

 » 16 months ago, # |   +147 I literally started missing vovuh
•  » » 16 months ago, # ^ |   +10 Yes we all do :(
•  » » 16 months ago, # ^ | ← Rev. 2 →   +450 Hi everyone who mentioned me in this blog (I wonder that there are so many mentions!). I didn't do any rounds because of my university exams period. But now it is ended and I'm done with it. So I'll return a bit later with another Div.3 round (I need time to come up with problems, discuss and prepare them). Do not worry about me, I am fine :)
•  » » » 16 months ago, # ^ |   +23 and being so busy you found time to reply us all. Thats what increases our love for you.
•  » » » 16 months ago, # ^ |   0 Then i am excited to see you participate in some div3 rounds.
•  » » » » 16 months ago, # ^ |   0 I had completed solved 2 question in yesterday contest and without any wrong submission then my rank decrease by 85 points with 123 penalty.....and I had submitted a wrong solution..........anyone have clear my doubts.....
•  » » » 16 months ago, # ^ |   0 we are for div-3 and div-3 for you
•  » » » 16 months ago, # ^ |   0 More up-vote than the main one.. it's all about vovuh popularity :3 <3
•  » » 16 months ago, # ^ |   -39 Is it rated.
•  » » » 16 months ago, # ^ |   +43
•  » » » 16 months ago, # ^ |   0 yes, if your rating is less than 1600 Div 3 contest will be rated for you. but as I can see you are unrated so yes this contest will be rated for you
•  » » » » 16 months ago, # ^ | ← Rev. 2 →   0 Hmm, then why am I not rated for this contest?Edit: Sorry, I didn't know that it just need to be waited.
•  » » » » » 16 months ago, # ^ |   0 Rating gets change after 12 hours of hacking phase, in Div. 3
•  » » » » » » 16 months ago, # ^ |   0 My rating still isn't changed, it's been 17 hours
•  » » » » » » » 16 months ago, # ^ |   0 Same here, no rating changes.
•  » » » » » » » » 16 months ago, # ^ | ← Rev. 2 →   +1 Same my friend's ratings have been changed but my rating is not changed till now.
•  » » 16 months ago, # ^ |   +1 And I started missing Vova in the contest. Spoiler: https://codeforces.com/contest/1324/problem/E
 » 16 months ago, # |   +9 how can I become a tester?
•  » » 16 months ago, # ^ |   -38 if you mean software tester tutorial i advice you to watch edureka playlist in youtube ♥
 » 16 months ago, # |   -64 Editorial before contest ;)
•  » » 16 months ago, # ^ |   +57 this ain't codechef! ;p
•  » » » 16 months ago, # ^ |   0 CodeChef_admin teja349 Look what world thinks about you. Thanks to the long challenge
•  » » » » 16 months ago, # ^ |   +4 There is a lot of cheating going on codechef long long challenge. Search on Telegram, there a special group ( dont remember exact name but its similar to "codechef discussion" ) dedicated to discuss the test cases and solutions.Also on YouTube found some guys explaining the solutions in comment boxes.
•  » » » » » 16 months ago, # ^ |   +24 I really dont know why u try to blame codechef or codechef admin for such thing. They are just organising contest they are not saying u to cheat and u know what its people like u who cheat in the contest search for links on telegram and so so... and really dont know why people cheat just to gain good rating ... well my friend rating at any platform wont fetch u any job or such its the knowledge that can ... so just stop blaming and start studying
•  » » » » » » 16 months ago, # ^ | ← Rev. 3 →   -27 Can you please write properly?"u" instead of "you" is irritating and also you're not texting someone that you are using "......".Just Stop this ! Edit:- If disliking this comment, could change my mind? :P
•  » » » » » 16 months ago, # ^ |   0 Hell yeah!! The name of telegram grp is exact same. Another reason to scrap long. I saw people there are congratulating each other and saying I got +210, i got +190 blah blah. And when i saw the shared files and photos then i realised how they acheived so. I still remeber codechef used to be good platform but now it is not so, you will barely see any (non indian) suggesting codechef. It can still regain its glory but for that they have to take some serious action and yeah plagiarism detector in long challenge is ineffective as one can easily make changes in entire code as long challenge is very supportive in such case as it give plenty of time
•  » » » » » » 16 months ago, # ^ |   +52 Forget about non-Indian...I barely see any Indian suggesting Codechef nowadays XD...
•  » » » » » » » 16 months ago, # ^ |   0 Some Indians still do :/
•  » » » » » » » 16 months ago, # ^ |   0 Exactly, we don't recommend Codechef to our college juniors. :/Codeforces is <3
•  » » » » » » 16 months ago, # ^ |   0 i dont think high rating matter in any way....it might be just to show off in in between your friend and even there also you will feel disrespected when you shall not be able to ans maybe a simple question to your friend.
•  » » » » 16 months ago, # ^ |   0 He's the codechef admin?!!!!!!!!
•  » » » » » 16 months ago, # ^ |   0 I tagged codechef admin and cache they are different person. Cache was admin of this contest
•  » » » » » » 16 months ago, # ^ |   0 Oh I'm sorry.. I didn't notice that was a separate handle..
•  » » » » » » » 16 months ago, # ^ |   -15 dont say sorry bro... things happen and you have to move on.
•  » » 16 months ago, # ^ |   0 You are my favorite pepega.
 » 16 months ago, # |   +59 vovuh Will always be in our memory
•  » » 16 months ago, # ^ |   +10 stop saying that he will be back soon.
 » 16 months ago, # |   +30 Consecutive div3 without vovuh :|
•  » » 16 months ago, # ^ |   0 Shut up
 » 16 months ago, # |   0 Good luck everyone!
 » 16 months ago, # |   -32 Hope solving upto C will be enough to increase rating for newbies like me :|
•  » » 16 months ago, # ^ |   +11 hope is a good thing.
•  » » » 16 months ago, # ^ |   +7 probably one of the best.!
•  » » » » 16 months ago, # ^ |   +10 "...maybe the best of things..."
•  » » » » » 16 months ago, # ^ |   +11 And no good things ever dies.
 » 16 months ago, # |   0 I wish all rated(<1600) users in this DIV-3 will be Unrated in the next coming div-3 rounds! :-)
•  » » 16 months ago, # ^ |   +25 if talking logically, this is not possible.
 » 16 months ago, # | ← Rev. 2 →   +7 I'm just curios, did vovuh retire?Also almost-copy-pasted-part is a lie. :(
•  » » 16 months ago, # ^ |   +2 he has not retired bro.... he is just a bit tired.
•  » » » 16 months ago, # ^ |   +5 He's a bit retired
•  » » 16 months ago, # ^ |   +15 May be vovuh is busy making a nice Div3 as after so many successive Div 3s He might have gone out of problems, but I feel that he will be back soon with a lot of quality problems.
•  » » » 16 months ago, # ^ |   +1 I hope so.
•  » » 16 months ago, # ^ |   0 Check his reply of first comment.
•  » » » 16 months ago, # ^ |   0 Thanks, ill be looking forward to it!
•  » » 16 months ago, # ^ |   0 Read this comment Hopefully, it will clear all your doubts.
•  » » » 16 months ago, # ^ |   0 Thanks.
 » 16 months ago, # |   0 I have only taken part in one rated contest, I guess this one's unrated for me.
•  » » 16 months ago, # ^ |   +2 you are rated.. Read the line carefully >> "Regardless of whether you are a trusted participant of the third division or not, if your rating is less than 1600, then the round will be rated for you."
 » 16 months ago, # |   +210
•  » » 16 months ago, # ^ |   0 told ya he needed warm up :))
•  » » 16 months ago, # ^ | ← Rev. 3 →   0 .
•  » » » 16 months ago, # ^ | ← Rev. 2 →   +22 Come on, I am here for a year practising almost every day for monthsIs this how months of practice looks like? There is a reason why people who are green are green.Edit: I used Codeforces Visualizer to plot this.
•  » » » » 16 months ago, # ^ |   +14 Destruction level 1e9 + 7. xD
•  » » » » » 16 months ago, # ^ | ← Rev. 2 →   -25 .
•  » » » » » » 16 months ago, # ^ |   +5 The graph clearly shows "Your way of practice". Mine is even poorer than yours and I clearly know what my way of practice is.
•  » » » » 16 months ago, # ^ |   0 BTW which website is it ?
•  » » » » » 16 months ago, # ^ |   0 i think it's this
•  » » » » 16 months ago, # ^ |   0 Sorry I'm new here. How do I know the rating of a problem? How do I get problems of a particular rating? And how can I access such data for myself?Ty :)
•  » » » » » 16 months ago, # ^ |   +3 Problemset. Here you can filter problems according to it's rating. The filter is on the right.
•  » » » » » » 16 months ago, # ^ |   0 Thanks! What level of problems should I be solving relative to my rating?
•  » » » » » » » 16 months ago, # ^ | ← Rev. 3 →   0 It varies from person to person.Looking at your graph you should probably be trying problems ranging from 1400-1700(same as mine) .If you find it too difficult gradually,come down to easier questions and practice them till you get a firm grip.If you find the questions easily solvable ,move up to higher rated problems.Always remember the key point is solving problems slightly above your comfort zone.You can use various sites like a2oj (https://www.a2oj.com/Ladders.html) and (https://www.a2oj.com/Categories.html) and code-drills(https://recommender.codedrills.io/) to practice as well.
•  » » » » 16 months ago, # ^ |   0 Where can i find this graph for myself?
•  » » » » » 16 months ago, # ^ |   0
•  » » » » 16 months ago, # ^ | ← Rev. 2 →   0 .
•  » » » » » 16 months ago, # ^ |   0 You have almost the same solve count as me on Stopstalk. But, It's hard to measure the difficulty of those numbers. Try doing more 1400-1500-1600 difficulty problems on Codeforces. By the time you do more than 100 of >=1500 problems, you won't be pupil anymore.
•  » » » » 16 months ago, # ^ |   0 chilla chilla ke sabko scheme bata de.
•  » » 16 months ago, # ^ |   +7 that's great I demoted to pupil
 » 16 months ago, # | ← Rev. 5 →   -78 i am feeling depressed now.....please upvote me.
•  » » 16 months ago, # ^ |   -47 if you disliked the comment above you should also dislike this comment too.
• »
»
»
16 months ago, # ^ |
-47

# couple_goals

 » 16 months ago, # |   +20
 » 16 months ago, # |   0 When you are at 1562 after a pretty good previous round.****Regardless of whether you are a trusted participant of the third division or not,if your rating is less than 1600, then the round will be rated for you.Hell yeah! It's time to go to pupil because of alt accounts (and 4WAs on A cause I suck) I guess.
 » 16 months ago, # | ← Rev. 2 →   -55 Always in Div.3 contest
•  » » 16 months ago, # ^ | ← Rev. 2 →   +18 why this meme looks like almost-copy-pasted?
 » 16 months ago, # |   0 Hope it will be an interesting round !!!
 » 16 months ago, # |   -33
•  » » 16 months ago, # ^ |   +11 Stop posting shit man
•  » » » 16 months ago, # ^ |   +8 ok Boss.
 » 16 months ago, # |   +6 my first div 3 contest as an expert excited
•  » » 16 months ago, # ^ |   +3 Now you can play without tension...I don't know when I will be a expert
 » 16 months ago, # | ← Rev. 2 →   +86 No offence .. It's just a meme ..
•  » » 16 months ago, # ^ |   0 Thats mah true comrade from reddit ;)Upvoted !!!
 » 16 months ago, # | ← Rev. 2 →   +14 We are missing vovuh
•  » » 16 months ago, # ^ |   0 Did you mean the other way around? I guess Vovuh and Stepavly should be swapped in this.
•  » » » 16 months ago, # ^ |   +11 Actually I have kind of lost my mind in this lockdown.
 » 16 months ago, # |   -44 We are getting almost copy pasted blogs, one day we will get almost copy pasted problems.
•  » » 16 months ago, # ^ |   +18 yeah you can make your own codeforces for that
•  » » » 16 months ago, # ^ |   0 If I can be a pro, I will make it surely
•  » » » » 16 months ago, # ^ |   0 that shall be great to make questions based on editorial
•  » » » » 16 months ago, # ^ |   +6 What do you mean by "pro"? Like GM or LGM?
•  » » 16 months ago, # ^ |   0 Why one day, visit interviewbit for the same today.
•  » » 16 months ago, # ^ |   +1 I think spending time on problems is of greater importance than spending time on writing beautiful or new blogs
•  » » 16 months ago, # ^ | ← Rev. 2 →   0 This guy gotta be a genius.
 » 16 months ago, # |   +7 RIP — vovuh, heh i will miss your contests(
•  » » 16 months ago, # ^ |   0 Hope vovuh will be back for next div 3 contest.
 » 16 months ago, # |   -6 Hope this round will give me positive rating change.
•  » » 16 months ago, # ^ | ← Rev. 2 →   +11 Just make 1 submission (correct or wrong doesn't matter) and then even God can't stop you from getting positive rating change. XD #newratingsystem
•  » » » 16 months ago, # ^ |   0 Sounds Good
•  » » 16 months ago, # ^ | ← Rev. 2 →   0 Ever heard this?I_love_Mia_Malkova When you stop loving the one you love you start getting the one you want. So true!
 » 16 months ago, # |   -22 All Div-3 contests Div-3 Round 1 http://codeforces.com/contest/977 Div-3 Round 2 http://codeforces.com/contest/978 Div-3 Round 3 http://codeforces.com/contest/988 Div-3 Round 4 http://codeforces.com/contest/999 Div-3 Round 5 http://codeforces.com/contest/1003 Div-3 Round 6 http://codeforces.com/contest/1005 Div-3 Round 7 http://codeforces.com/contest/1006 Div-3 Round 8 http://codeforces.com/contest/1015 Div-3 Round 9 http://codeforces.com/contest/1029 Div-3 Round 10 http://codeforces.com/contest/1066 Div-3 Round 11 http://codeforces.com/contest/1077 Div-3 Round 12 http://codeforces.com/contest/1092 Div-3 Round 13 http://codeforces.com/contest/1095 Div-3 Round 14 http://codeforces.com/contest/1102 Div-3 Round 15 http://codeforces.com/contest/1108 Div-3 Round 16 http://codeforces.com/contest/1118 Div-3 Round 17 http://codeforces.com/contest/1133 Div-3 Round 18 http://codeforces.com/contest/1141 Div-3 Round 19 http://codeforces.com/contest/1144 Div-3 Round 20 http://codeforces.com/contest/1154 Div-3 Round 21 http://codeforces.com/contest/1157 Div-3 Round 22 http://codeforces.com/contest/1165 Div-3 Round 23 http://codeforces.com/contest/1176 Div-3 Round 24 http://codeforces.com/contest/1183 Div-3 Round 25 http://codeforces.com/contest/1196 Div-3 Round 26 http://codeforces.com/contest/1203 Div-3 Round 27 http://codeforces.com/contest/1213 Div-3 Round 28 http://codeforces.com/contest/1216 Div-3 Round 29 http://codeforces.com/contest/1234 Div-3 Round 30 http://codeforces.com/contest/1249 Div-3 Round 31 http://codeforces.com/contest/1256 Div-3 Round 32 http://codeforces.com/contest/1272 Div-3 Round 33 http://codeforces.com/contest/1283 Div-3 Round 34 http://codeforces.com/contest/1294 Div-3 Round 35 http://codeforces.com/contest/1296 Div-3 Round 36 http://codeforces.com/contest/1311 Div-3 Round 37 http://codeforces.com/contest/1324 Div-3 Round 38 http://codeforces.com/contest/1328 Div-3 Round 39 https://codeforces.com/contest/1335 Div-3 Round 40 https://codeforces.com/contest/1343 Div-3 Round 41 https://codeforces.com/contest/1353 Div-3 Round 42 https://codeforces.com/contest/1360
•  » » 16 months ago, # ^ |   +9 I used to do the same until I found this.
•  » » » 16 months ago, # ^ |   0 You could use this too.
•  » » 16 months ago, # ^ | ← Rev. 2 →   0 https://surya1231.github.io/Codeforces-contest/follow this to get the links of all the contests of codeforces. you can also check the problems that you could not solve so that you can upsolve it later.
•  » » 16 months ago, # ^ |   0 get it in your blog !!
 » 16 months ago, # |   0 What does a penalty of 10 minutes mean? If you have a wrong answer submission you lose ten minutes?
•  » » 16 months ago, # ^ |   +4 The points you lose for submitting 10 min later will be the points deducted for 1 wrong submission.
•  » » 16 months ago, # ^ |   +2 Let's take an example. Suppose you are submitting your question A after 5 minutes of contest's start time. If it is going to be correct you will be given penalty of just 5(minutes to solve question). Now suppose it is wrong on some test case.You find fault in logic and submit it after 15 minutes from the start time. So total penalty for this question would be 15(minutes to solve question) + 10(for 1 wrong submission)=25. For every wrong submission you will be awarded with 10 minutes penalty. I hope this cleared your doubt about 10 minutes penalty.
•  » » » 16 months ago, # ^ |   -8 You could have simply said that we get 10 minutes behind than the actual submission time.
•  » » » » 16 months ago, # ^ | ← Rev. 2 →   +3 Well I tried my best to explain him 10 minutes behind the actual submission time.....
 » 16 months ago, # |   0 Live upsolving 5 mins after the round ends: https://youtu.be/Fcxm3iROflIGood luck!
 » 16 months ago, # |   -25
•  » » 16 months ago, # ^ |   -30 Stfmu! Having a good dayShut the fucking meme up!
•  » » » 16 months ago, # ^ |   -16 My guy almost thought he is going to get +ves for the comment ((
•  » » » » 16 months ago, # ^ |   -10 You see LIGHT in my profile pic..?YES!! I've always admired THE negative. [wicked smile]
•  » » 16 months ago, # ^ |   0 not when u code in python:)
 » 16 months ago, # |   +38
 » 16 months ago, # |   +10 vovuh will you make div(1, 2) contest in the future??most of the participants will be looking forward to the contest that you are making.good luck to everyone who are participating in this contest!!!and if you are interested and don't know look into it(there is an extension which predicts your score change after contest called CF-Predictor)(Good luck & high rating!)
•  » » 16 months ago, # ^ |   +14 Div. 2 maybe sometimes, when I come up with good and hard enough problems. Not sure about Div. 1 :)
•  » » 16 months ago, # ^ |   0 CF-Predictor disabled today.!!
•  » » » 16 months ago, # ^ |   0 No, it's not :)
 » 16 months ago, # |   0 I come here for the memes.
•  » » 16 months ago, # ^ |   -10 You copied me :(
•  » » » 16 months ago, # ^ |   -16 Haha! This was pure coincidence. :p And for some consolation. You got some upv,I have zero ;)
•  » » » » 16 months ago, # ^ |   0 What, was it a notorious coincidence?
•  » » » » 16 months ago, # ^ |   0 now you have negative.
 » 16 months ago, # |   +7 You have 6 Hrs 30 Min to provide fastest editorial. :)
 » 16 months ago, # |   +28
 » 16 months ago, # |   +30 I thought vovuh was a university student... Though youth doesn't prevent him from being strong and orzable.
•  » » 16 months ago, # ^ |   +19 Actually, I am stupid and "high school" was a semantic typo because I don't remember what is high school exactly and of course because I am stupid. Sorry :(
•  » » 16 months ago, # ^ |   0 What does orzable have to do with it?
•  » » » 16 months ago, # ^ |   +3 hehe only just saw this xd
 » 16 months ago, # | ← Rev. 2 →   -59 Is it rated?
•  » » 16 months ago, # ^ |   +12 Downvotes would have surely given you the answer....
 » 16 months ago, # |   0 waiting for this contest <3
•  » » 16 months ago, # ^ |   -9 Don't wait for something to happen, Make it happen.
 » 16 months ago, # |   0 Good luck to y'all.
 » 16 months ago, # |   0 Good Luck!
 » 16 months ago, # |   +3 Worst Problem Today: CF Predictor is disabled.
•  » » 16 months ago, # ^ |   +3 I've updated the extension, you probably didn't accept new permission. Please let me know if you have latest version of the extension (1.3.0) it's enabled and still doesn't work.
 » 16 months ago, # |   0 "do not have a point of 1900 or higher in the rating." 1900 or1600?
•  » » 16 months ago, # ^ |   +22 lets say at some point in time you've been 2000. then you do a huge drop and go to 1200. in this situation your current rating is under 1600, but you have a point in which your rating has been above 1900 and because of that div3 will not be rated for you. hope that helped
 » 16 months ago, # |   0 hope to solve a b c or a b c d
 » 16 months ago, # |   -6 Looks like most unbalanced Div 3 ever. Solve first 3 and then netflix and chill.
•  » » 16 months ago, # ^ |   -10 its unfair and worst Div. 3 ever.
 » 16 months ago, # | ← Rev. 3 →   -7 stringforces!
 » 16 months ago, # |   0 Now that's a damn great contest. My best ever. Thank you Stepavly!
 » 16 months ago, # |   -50 Worst contest of all time.
•  » » 16 months ago, # ^ |   -21 same to me..a b solved with 8 min..but c killed me..i solved at last with 6 WA.
 » 16 months ago, # |   0 notDiv3 Forces
 » 16 months ago, # |   +24 Comments summarized - Make Div.3 great again. Bring vovuh back.
•  » » 16 months ago, # ^ |   +21 Today's contest was great. wasn't it?
•  » » » 16 months ago, # ^ | ← Rev. 3 →   +18 yes but I think problems are more suitable for DIV-2.
•  » » » » 16 months ago, # ^ |   +7 Yeah, i agree that problems were tougher than usual Div3's.
 » 16 months ago, # |   +1 Could you anyone explain answer 15-beautiful to the task E? 20 10 aaebdbabdbbddaadaadc Counts: [a,b,c,d,e] [7,5,1,6,1] 
•  » » » 16 months ago, # ^ |   0 Swap b and d, you have 6x b but there are only 5.
•  » » » » 16 months ago, # ^ |   +3 oops!! Thanks :)
•  » » 16 months ago, # ^ |   +1 aabddaabddaabdd
 » 16 months ago, # |   +1 As usual xD.D always alot harder than C
 » 16 months ago, # |   +8 F1 seems weirdly familiar: https://codeforces.com/contest/606/problem/C
•  » » 16 months ago, # ^ |   +8 Yeah..XD.. But i had found it in codechef https://www.codechef.com/PLIN2020/problems/BALASEQ
•  » » 16 months ago, # ^ |   +11
 » 16 months ago, # |   0 How to solve F1 !?
•  » » 16 months ago, # ^ |   0
•  » » 16 months ago, # ^ | ← Rev. 2 →   0 Find the longest increasing subsequence of the given array which is the subarray of the sorted version of that array. Some examples are good for this observation. Then the answer is n-size.
 » 16 months ago, # | ← Rev. 2 →   +15 C to D long difference -_-
•  » » 16 months ago, # ^ |   0 Hey, how to upload a meme?
•  » » » 16 months ago, # ^ |   +5 upload image on imgflip.com you can add some text on the picture. copy the link and paste in the comment picture option.
•  » » » » 16 months ago, # ^ |   0 i think you should focus more on coding than memes
 » 16 months ago, # |   0 corner cases in C sucked the crap outta me
•  » » 16 months ago, # ^ |   0 same to me ..just 1 case fully sucked me.
 » 16 months ago, # | ← Rev. 2 →   0 How to solve C? This one was hard for me
•  » » 16 months ago, # ^ |   +8 man are you nude in pic ?? !! hell !!
•  » » » 16 months ago, # ^ |   0 lol
•  » » » 16 months ago, # ^ |   0 Would it be okay with you if he'd worn a tie?
•  » » 16 months ago, # ^ |   0 3 parts, the 0s before first 1, the 0s between any two 1s in middle, and the 0s after the last 1.For the first, the answer would be + no of zeroes / k + 1. You can consider it like you need to enter k zeroes and a 1, so the total sequence you insert is k + 1 length. Similarly from the last 1. For the middle part, you need to insert k zeros, a 1, and again k zeroes at the end( only once). so answer for middle would be (no of zeroes — k) / k + 1.
•  » » » 16 months ago, # ^ |   0 I think I got it. Thank you very much
•  » » 16 months ago, # ^ | ← Rev. 2 →   0 between two 1 >> count number of zero ..count-=k and ans+=count/(k+1); and for first until found 1>> count number of zero ..and ans+=count/(k+1); and for last_1 to last>> count number of zero ..and ans+=count/(k+1); But if all zero then ans=(n+k)/(k+1);
•  » » » 16 months ago, # ^ |   0 Got it, I will try to answer it. Thank you very much
 » 16 months ago, # |   +2 What is this lol?https://codeforces.com/contest/1367/submission/84003910
•  » » 16 months ago, # ^ | ← Rev. 2 →   0 Trr chacha trrr haha ​​trrr wumbam trrr haha ​​dalung us nadi hafanana and on on cucarella shalalalaCelebration sounds..?
•  » » » 16 months ago, # ^ |   0
 » 16 months ago, # |   0 I submitted the solution for E here: https://codeforces.com/contest/1367/submission/84020235 It gives the correct output locally, as well as on codechef's online IDE. What's going on? Can anyone help?
 » 16 months ago, # |   +4 Can someone explain their approach to F? I was thinking that the answer is something along the lines of $n - LIS(a)$ but I couldn't prove it
•  » » 16 months ago, # ^ |   0 At first sight, I also thought the same. But the last test case lol !
•  » » 16 months ago, # ^ | ← Rev. 2 →   +8 Yes we have to find the LIS but it should also be the subarray of sorted version of that array.
•  » » 16 months ago, # ^ | ← Rev. 3 →   +3 There is one more condition that LIS should be consecutive in given sorted array.
 » 16 months ago, # |   +44
•  » » 16 months ago, # ^ |   -10 Hey, how to uploaed a meme?
 » 16 months ago, # |   0 Am I the only one who was facing difficulties in implementing D?I should have tried E first. Looking forward for short ways to implement D.PS. Solved D,5 mins before the contest ends. Fingers crossed for system tests.
 » 16 months ago, # | ← Rev. 2 →   +7 Problem F1 is a variation of this problem: https://codeforces.com/contest/1231/problem/E
 » 16 months ago, # |   +4 The problems were nice!But the Huge difficulty gap between Problem C and D made the contest "FastTypeForces" !
 » 16 months ago, # | ← Rev. 2 →   0 Can Anybody tell that is there any corner case in Problem C? Getting WA on test 2. Solution — 84019963
•  » » 16 months ago, # ^ | ← Rev. 4 →   0 Brother your solution is failing on some test cases... One examplen=5 k=1string= 10100Your output= 0Answer should be= 1 (10101)Please check your code accordingly.......
•  » » » 16 months ago, # ^ |   +3 Thanks Brother for replying,I think Answer should be 1. Why are you counting the '1' which is already given? we have to find additional tables that we can occupy.
•  » » » » 16 months ago, # ^ |   0 Friend now i have updated my comment...Sorry for last wrong comment... This time I think i have found test case giving wrong answer to your solution
•  » » » » » 16 months ago, # ^ |   0 Thank you Friend, I got my mistake!
 » 16 months ago, # |   0 Dont konw why get WA on 3 in problem D until the end of the contest. Interesting maybe I implement something stupidly wrong.
 » 16 months ago, # |   0 Tough div3 round!!
 » 16 months ago, # |   0 For problem D , can someone help me ?https://codeforces.com/contest/1367/submission/84022026My code is giving correct o/p if i use number of test cases as 1. but for multiple test cases its giving wrong output in some weird format, any help will be appreciated !
 » 16 months ago, # |   0 I found the answer for F1 as n — (longest sorted subsequence length). Why doesnt the same logic work for F2? My logic was basically keeping the already sorted things at their place and moving other numbers to sort them.
•  » » 16 months ago, # ^ | ← Rev. 2 →   0 142 0 0 3Longest sorted subsequence is 0 0 3, but you cannot move 2 to the middle in one move.
•  » » » 16 months ago, # ^ |   0 By longest sorted subsequence i did not mean Longest increasing subsequence. Sorry for the confusion. What i meant was if we sort the given sequence lets say S = 2 0 0 3and the sorted sequence becomes S' = 0 0 2 3I am calling the longest sorted subsequence as the largest subsequence in S which is a substring of S'. So for your example it will be 0 0 and the answer comes to be 2. Again, sorry for the confusion of terminology.
•  » » » » 16 months ago, # ^ | ← Rev. 4 →   +3 it will work, your way of finding the lis which occurs as sorted subarray is wrong. let's compress the array so that it contains elements from 1 to n. The problem is when an element(let's say $x$ and $x$ -1 is already taken in LIS) has multiple occurences than we need to ensure that if we take $x$ + 1 then all the occurrences of $x$ are already taken in LIS. This is the thing you are missing (i too missed this).
•  » » » » » 16 months ago, # ^ | ← Rev. 2 →   0 I do not think i missed it but i will check again :) Thank you :)
•  » » » » 16 months ago, # ^ | ← Rev. 2 →   0 How does one come up with such observation? Its like, I thought of LIS but after seeing the last sample test case I thought may be this observation of mine is farfetched. Do I need to solve similar questions before I get any close to acing div2 and div3?
•  » » » » » 16 months ago, # ^ |   0 https://codeforces.com/problemset/problem/1363/Fi couldnt understand the question to the link i gave you, before. Its editorial had similar wording. So while i was trying F i thought of the operation as cyclic shifts and modeled it similar to this question. I remembered in the actual editorial (there was an editorial of this question which i cannot find link to, this question was copied from there). In the actual editorial they talk about if both types of shifts were allowed. So i modeled on that solution. I think in the end it is how many questions you have solved and how much did you learn from them. Keep solving and you will get these questions soon :)
•  » » 16 months ago, # ^ |   0 if i take the elements in pairs as{ element value,index} and then sort the array based on its element value and then find the largest increasing subsequence for the index part,will it work?
 » 16 months ago, # |   0 StringForcessss
 » 16 months ago, # |   0 bring back vovuh
 » 16 months ago, # |   -9 Nice round! Was 1 min too late to get D.
 » 16 months ago, # | ← Rev. 2 →   +1 In my opinion too hard problems for div 3 and I felt like it was div 2 with more problems than usual
 » 16 months ago, # |   +3 D is for div2
 » 16 months ago, # |   +9 Problem F is very similar https://atcoder.jp/contests/agc024/tasks/agc024_b?lang=en , but I can't solve F2 ( ；∀；)
 » 16 months ago, # |   0 How can i solve D and E? I solved A,B,C fast but I can't get an idea how to solve these two
•  » » 16 months ago, # ^ | ← Rev. 3 →   0 Problem D Let $X$ be the number of position $i$ such that $B_i$ is $0$ and $t_i$ is still undetermined. Choose the biggest character $c$ such that it is unused, smaller than any already used character and it appears at least $X$ times in $s$. Assign $c$ to all of those $X$ positions described in the previous step. For all the position $j$ where $B_j$ is non-zero, subtract $|i-j|$ from $B_j$ for each position $i$ of those $X$ positions we got in the first step. Repeat these steps until all the characters of $t$ are determined.
 » 16 months ago, # |   0 Codeforces should add a new feature for rating a round. from C to D hardness jumped like anything and this isn't good for us. at the last it was just a typing round. maybe testing could have been better.
 » 16 months ago, # |   0 Here's how I solved D:We have our array b. We start filling our final string at those positions where b[i]=0 {because we can fill all these positions with greatest alphabet having relevant count}. This means, first iterate over string and calculate count of each character in our original string s. Now, at each iteration, we fill all indices at which b[i]=0 with the character that is lexicographically greatest, and has a count greater than or equal to no. of indices having b[i]=0. Dont forget that with increasing iterations, the character in the final string that you fill in at all 'i's such that b[i]=0; should decrease lexicographically.Also at each iteration, for each index value where b[i]=0; update the values in array b for every j (b[j]!=0) by b[j]= b[j]-abs(j-index[i]) {where lets say index array contains all positions in b where b[i]=0}. This is done to ensure that the contribution of positions we've already filled, is not taken further into account while filling the final string in further iterations.Do these iterations uptil the level, all positions in the final string are assigned some character.You can visit my profile and see my code. Its pretty understandable.Btw It was a beautiful contest. I couldn't have time to solve E although it seemed doable to me.
•  » » 16 months ago, # ^ |   +25 ..
 » 16 months ago, # |   0 Was E today easier than usual div3 Es?
•  » » 16 months ago, # ^ |   0 slightly but it is ok it was more because D was hard
 » 16 months ago, # |   +2 why there are hacks on D?
 » 16 months ago, # |   0 Video Tutorial C:https://www.youtube.com/watch?v=lCNk_D5m6-I
 » 16 months ago, # |   -9 LOL F1 was much easier than D,E
 » 16 months ago, # |   +86 Ashishgup is back!!
 » 16 months ago, # | ← Rev. 2 →   0 Edit: Found a simpler method.
 » 16 months ago, # |   0 I got this diagnostics from my submission 84025940 for 1367D - Task On The Board. Does anyone know what this means?
•  » » 16 months ago, # ^ |   0 The error is in reference with the cf evalutor, read the check log you will get it. Yours code is generating warnings but no compilation or runtime error. The ans it is printing is causing the error in the evaluator
 » 16 months ago, # |   +1 F1 is very similar to this problem from SPOJ which I already solved. I didn't read F1 during the contest (thinking it would be very difficult) and now I submitted the same code just with one change and got accepted :-( and F1 is more easier than D and E
 » 16 months ago, # |   +8 What's the meaning of giving such useless pretests? Isn't it better to run the whole dataset after the contest and no testcase run during the contest? If pretests of problem D didn't give the AC verdict,I would make some cases and run them for my code. The case missing in the pretest set is like: 1 aaabbc 4 3 2 1 0Simple and necessary case. What's the meaning of pretests? mocking?
•  » » 16 months ago, # ^ |   +3 Exactly my question. If you don't even care enough to give some critical in pretests what's the use of even giving some of those?Many setters even exclude all the critical cases intentionally to make every contestant suffer after the contest ends. I don't actually get the actual reason behind this. Contestants love a contest with some strong pretests, not your silly evil game.
•  » » » 16 months ago, # ^ |   0 You should work on testing your own code. TopCoder for example gives very simple pretests. If pretests catch everything, then hacks will be impossible.
•  » » » » 16 months ago, # ^ |   0 Yeah, I guess. The best thing we can do from our side to write the cleanest as possible code possible, I guess.
•  » » 16 months ago, # ^ | ← Rev. 2 →   +3 mian hehe
•  » » » 16 months ago, # ^ |   +5 I have hacked my own submission with this case. I will be pleased to know how the case is invalid.
•  » » » 16 months ago, # ^ |   +5 You might have given 1 aaabbc 4 3 2 1 0 in the hack. The correct format is 1 aaabbc 4 3 2 1 0
•  » » » » 16 months ago, # ^ |   +8 You were right. My bad
•  » » » » » 16 months ago, # ^ |   +5 No worries, thanks.
•  » » 16 months ago, # ^ |   0 The first example case tests the same thing and your code somehow gets marked as OK despite an invalid answer. I don't think the pretests are weak, I think the checker is broken.
•  » » » 16 months ago, # ^ |   0 No, I was not taking care of the frequency. Say, I want to put a character in the indexes where b[I] = 0. Let, I have chosen character 'x' and I don't have enough characters to put in the indexes where b[i] = 0. My code was not handling that and got AC. It's not fair at all.
•  » » 16 months ago, # ^ |   -78 MikeMirzayanov Stepavly Supermagzzz What the FUCK man. You FUCKING FUCK.
•  » » » 16 months ago, # ^ |   +33 GET OUT FROM CODEFORCES.
 » 16 months ago, # | ← Rev. 2 →   +24 MikeMirzayanov Stepavly i wonder how did this pass ? the complexity is O(n*n*n) 84019953
•  » » 16 months ago, # ^ | ← Rev. 2 →   0 The sum of n for all test cases in one test does not exceed 3000.I THINK its ok with the constraints.
•  » » » 16 months ago, # ^ |   +3 3000^3 should be TLE :/
•  » » » » 16 months ago, # ^ |   0 I think it is $\frac{3000^3}{8}$, which is aprox 3e9 and slightly fits into 2000ms.
•  » » 16 months ago, # ^ |   +3 Your algorithm has a good constant factor and TL is quite big.
•  » » 16 months ago, # ^ |   0 it's just O(n*n)
•  » » » 16 months ago, # ^ |   +19 No, the memoization is useless.
•  » » 16 months ago, # ^ |   +11 Maybe it's due to compiler optimization... The algorithm is exactly $O(n^3)$ but the compiler greatly optimized it...In fact, that program need to run about $4.5*10^9$ operations in the worst case (when $a_i$ is strictly increasing), which should take over $20$ seconds without optimization :(
•  » » » 16 months ago, # ^ |   +14 Yes I know that my program need to run 4.5e9 in the worst case .. and i tried to hack it but i couldn't .. so i think that is unfair :/
 » 16 months ago, # |   0 Can any one Explain E problem? Thanks in advance 
•  » » 16 months ago, # ^ |   +1 I discuss the solution with pictures at 2:02:12 in this video.
 » 16 months ago, # |   +17 For people who prefer video editorials, I discuss the solutions to all problems at the end of my screencast of the round.
 » 16 months ago, # |   0 I hope "accepted" and "pretest passed" will not follow the rule of social distancingbut vovuh should not keep social distancing from Div3
 » 16 months ago, # |   0 83942386 why is it giving MLE for the first question ????
•  » » 16 months ago, # ^ |   0 because of this array int divisors[100000000] ={0};https://codeforces.com/contest/1367/submission/84033068check this one same as your code but without this array
•  » » » 16 months ago, # ^ |   0 thank u buddy
 » 16 months ago, # |   +5 Is there some problem with the checker for Problem D ? For the case- aabc 3 2 1 0 Many submissions give "bbc" as output and checker give them Ok response
•  » » 16 months ago, # ^ |   +6 Exactly! :/ I think this ruined the contest.
•  » » 16 months ago, # ^ |   +3 Poor Testing! Disappointed! Test cases accepting wrong answers too.
•  » » 16 months ago, # ^ |   +1
 » 16 months ago, # |   0 It was my second contest and again I could only solve a single problem, for the second problem I could only solve the visible test case, and couldn't think of the hidden test case, one of the major pain points, not being able to be creative enough to be able to think through the test case, feels like not having the brains or observational skills, any advice to how can I work to improve on this??
•  » » 16 months ago, # ^ | ← Rev. 2 →   0 Only things which can make you better is 1st SpoilerPractice and Hard work And Spoiler 2more practice 
 » 16 months ago, # |   0 why am i getting this error in trying to hack a solution ? Validator 'validator.exe' returns exit code 3 [FAIL initial string should satisfy distance condition (test case 1) can anyone help ?
•  » » 16 months ago, # ^ |   0 I guess you are talking about problem C.From error it seems that that you are entering string that itself is not satisfying the condition of minimum distance. Eg. For n=5 and k=1 you cannot enter input string as 10011
•  » » » 16 months ago, # ^ |   0 thanks.
 » 16 months ago, # |   0 why not my dashboard is not showing i have participated in this contest and even not any changes in rating
•  » » 16 months ago, # ^ |   0 i can see you in the standing and wait for rating change.
 » 16 months ago, # |   0 Is the round rated yet?
•  » » 16 months ago, # ^ |   0 Same with me. There are no changes in the ratings. It might be a bug or any other issue as codeforces was down for some time. Let's see what happens.
•  » » 16 months ago, # ^ |   0 Of course . Just need to wait.
 » 16 months ago, # |   0 Have all the submission's been re-judged after the hacking phase? it doesn't look like it.
•  » » 16 months ago, # ^ |   0 Same question, is system testing done?
•  » » » 16 months ago, # ^ |   0 Yes, it says so in the standings.
•  » » » 16 months ago, # ^ |   +9 I don't think so....
 » 16 months ago, # |   +1 My solutions are in queue since 30 minutes!
•  » » 16 months ago, # ^ |   0 maybe server is down,once my solutions were in queue for 4 hours..
 » 16 months ago, # | ← Rev. 2 →   0 Hey all, I am a newbie and I saw many blogs about problem D of yesterday's contest . So I want to know that whether this contest is rated for me or not . I am able to solve only problem A and B
•  » » 16 months ago, # ^ |   0 Rated for you.rating change doesn't not related with newbie or you saw problem D in many blog..rated for all are rating less than 1600.
•  » » » 16 months ago, # ^ |   0 Ok fine but why till now no improvement in rating. Is it unrated ?
 » 16 months ago, # |   0 Hey i gave this contest and my rating is not updated yet I am new to codeforces how much time it takes to update rating??
•  » » 16 months ago, # ^ |   +10 The system testing is not complete yet, ones it is completed rating will get updated in 2-3 hours.
•  » » » 16 months ago, # ^ |   0 its complete ig coz the rankings arent changing anymore
•  » » » » 16 months ago, # ^ |   +1 It is not even started, only the hacking phase is completed.
•  » » » » » 16 months ago, # ^ |   +1 Yeah right
•  » » » » » 16 months ago, # ^ |   0 I was practicing on some old questions. The solution took some 30 mins to get judged and before that codeforces site was not working so I thought it was system testing for which they stopped everything
 » 16 months ago, # | ← Rev. 2 →   +1 solved E without graphs.. gcd and some basic operations : solution
»
16 months ago, # |
-28

Please help The judge and my local systems produce different answers even for given sample input output. The output on my system is identical to the required output but on running the judge i get the output as 3 for all the input test cases in the sample given

# include

using namespace std;

int v[1000000];

int main() { int t; cin >> t;

while(t--)
{
int n, k;
cin >> n >> k;

//Taking input
fflush(stdin);
for(int i  = 1; i <= n; i++)
{
int x = getc(stdin);
x = x - '0';
v[i] = x;
}

//Checking for any 1 in range 1..k
int pos = 1;
int ans = 0;
bool flag = false;

for(int i  = 1; i <= k; i++)
{
if(v[i] == 1)
{
flag = true;
pos = i;
break;
}
}
if(!flag)
{
ans++;
}

pos += k + 1;

while(pos  <= n)
{
//If one is present k positions away
bool isPresent = false;
for(int i  = pos; i <= pos + k; i++)
{
//If we reach end of list
if(i > n)
{
pos = n + 1;
isPresent = false;
break;
}

if(v[i] == 1)
{
isPresent = true;
pos = i + k + 1;
break;
}
}

//If one is absent k positions away
if(!isPresent)
{
ans++;
v[pos] = 1;
pos += k + 1;
}
}
cout << ans << endl;

}

}

 » 16 months ago, # |   0 Why has the rating not updated yet?
•  » » 16 months ago, # ^ | ← Rev. 2 →   +1 coz a lot of people aren't ready for that(including me)... XD
•  » » 16 months ago, # ^ |   0 Now system testing completed,so wait for 1-2 hrs..we will see soon!!
 » 16 months ago, # |   +85 In problem D, there was an issue in the checker program, which affected some participants. I am now investigating this incident. I'll exclude from the rating all those who were affected by this mistake. During the research, I will temporarily hide the problem from the contest, then it will return. I believe that the problem affected no more than a few percents of all participants in the round. I apologize: I was one of three people who read the checker but did not notice a typo in it.
•  » » 16 months ago, # ^ |   +13 But pls make sure those who have submitted correct , they should be rated with problem D,because i see a sudden drop in my standing
•  » » » 16 months ago, # ^ |   +8 Yes, the people who submitted it right must be given points for it and the system testing should be done again.
•  » » » 16 months ago, # ^ |   +1 Same thinking with you :(
•  » » » 16 months ago, # ^ |   +1 What's actually a hacking phase in codeforces? I'm new at it and I've seen people talking about hacking a problem or solution (don't know exactly what it is). Can someone explain about it little bit?
•  » » » » 16 months ago, # ^ |   +5 After the contest is over, your solution can be viewed by anyone. You can then run the solution on your custom testcases known as hacks. if the solution fails, then the hack is succesful.
•  » » » » »