### FieryPhoenix's blog

By FieryPhoenix, 5 months ago,

Hi Codeforces!

I’m thrilled to invite you to Codeforces Round #638 (Div. 2), which will take place on May/01/2020 17:35 (Moscow time). It's rated!

There will be 6 problems, and you will have 2.5 hours to solve them. All the problems are written and prepared by me.

Huge thank you to everyone who made this round possible:

I hope everyone will enjoy the problems! I have tried to make short statements and strong pretests. Hopefully this contest will be even better than my previous one :)

UPD: Thanks also to darnley for proofreading statements and suggestions!

UPD: The scoring distribution is standard: 500 — 1000 — 1500 — 2000 — 2500 — 3000

UPD: Editorial is here

UPD: Congratulations to the winners! I hope most of you enjoyed the round. If you have any questions, feel free to ask in the comments.

Overall Winners:

Div 2. Winners:

• +1358

 » 5 months ago, # |   +27 Thanks for your hard work making the contest, I love you <3
•  » » 5 months ago, # ^ |   +20 HOPE! to see some problem names starting with "Cows..."
•  » » » 5 months ago, # ^ |   0 agreed :p
•  » » » » 5 months ago, # ^ |   +15 Cowedforces. :-D
•  » » » 5 months ago, # ^ |   0 wow, that's very cool
•  » » 5 months ago, # ^ |   -48 +1
 » 5 months ago, # |   +8 Thank you Fiery for taking the time to write a contest for us. I am sure it will be a stellar contest since it was written by the god Fiery himself.
 » 5 months ago, # |   +12 It is going to be good contest! GL & HF for everyone!
 » 5 months ago, # |   0 Ahh, more ans more contests!! I like it..
 » 5 months ago, # |   +14 OMG BENQ TESTED A ROUND :O
•  » » 5 months ago, # ^ |   -90 OMG!!!
 » 5 months ago, # | ← Rev. 2 →   0 codeforces is saving me in this quarantine period.
•  » » 5 months ago, # ^ |   -11 All of us man
•  » » 5 months ago, # ^ |   +61 Situation be like:
 » 5 months ago, # |   +44 short statements and strong pretest very happy to see this
•  » » 5 months ago, # ^ |   +6 Agree, always loved to solve problems with short statements
 » 5 months ago, # |   +25 Looking forward to some FieryProblems with FieryPretests !!
 » 5 months ago, # |   -12 Thanks all of the writers and also a huge thank to Mike because of this amazing platform. Really looking forward to this contest.
 » 5 months ago, # | ← Rev. 3 →   -136 [Deleted]
•  » » 5 months ago, # ^ |   +31 Except yours.
•  » » » 5 months ago, # ^ | ← Rev. 3 →   -123 :((((((
•  » » » » 5 months ago, # ^ |   0 When people put "[Deleted]" on their comments, that just makes me want to downvote them more. I'm still gonna see the comment, but now I have to spend time pressing previous revision.
•  » » » » » 5 months ago, # ^ |   -10 How to do that? Where is the option / button for that?
•  » » » » » » 5 months ago, # ^ |   +17 On top of every edited comment, left of the upvote button.
•  » » » » » » 5 months ago, # ^ |   +11 If a comment has been edited, there would be ← Rev. 2 to the left of the upvote/downvote count (or a higher number if it's been edited multiple times).Click on that left arrow to go to the previous revision.
•  » » » » » » » 5 months ago, # ^ |   0 Cool thanks bro
•  » » » » » » 5 months ago, # ^ | ← Rev. 2 →   +9 I seriously don't understand why my above comment deserves downvotes I just thanked a person It's not like I care about my contribution , but I would like to know what it is that i said which is troubling people? [Edit: I posted this when there were 21 downvotes]
•  » » » » » » » 5 months ago, # ^ |   0 Downvoting frenzy :)
•  » » » » » 5 months ago, # ^ |   +60 Oky i wont edit them like that anymore, seems everyone has the same thoughts as you. In my opinion when someone deletes his/her comment, then it means he is shameful of what he said or he thinks his comment is nor fun neither helpful.
•  » » » » 5 months ago, # ^ |   -11 [Deleted]
•  » » » » » 5 months ago, # ^ |   +26 I have no idea why someone would upvote this.
•  » » » » » » 5 months ago, # ^ |   +10 Kindergarteners are easily amused.
•  » » » » » » » 5 months ago, # ^ |   +22 your rating curve is a nightmare....lol
•  » » » » » » » » 5 months ago, # ^ |   0 I am simulating white noise with it.
•  » » » » 5 months ago, # ^ |   0 WTF -125 0-0
 » 5 months ago, # |   +10 I'm Waiting eagerly to participate in this contest in the quarantine period. Hope it will create an excitement a bit more
 » 5 months ago, # |   +21 hope this will be wonderful
 » 5 months ago, # | ← Rev. 2 →   +10 Thanks to Codeforces for saving me from my boring time,which gives me more opportunities to get in touch with algorithm knowledge and make lots of like-minded friends.Thanks for your hard work to make this meaningful contest.I'm really looking forward to this contest!! Hope everyone have a good performance. Good Luck ! :)
•  » » 5 months ago, # ^ | ← Rev. 2 →   -45 [Deleted]
 » 5 months ago, # | ← Rev. 2 →   0 Can someone share his old contest's link ?
•  » » 5 months ago, # ^ | ← Rev. 2 →   0 Goto problemsetting tab from top of the blog. Here you will find all his previous contest.
•  » » 5 months ago, # ^ |   0
 » 5 months ago, # |   +5 thanks FieryPhoenix... thanks codeforces... the only friend i can visit yet *_^ Always at the peak :))
 » 5 months ago, # |   +21 I'm glad for the short statement. I hope the authors of future contests also think like you.
•  » » 5 months ago, # ^ |   0 contestants who are bad at english also think like you :)
•  » » » 5 months ago, # ^ |   0 hahaha, maybe!
 » 5 months ago, # |   +11 It will be great if there is no links in the statements:) -> it always takes me a long time to open them.:(
 » 5 months ago, # | ← Rev. 2 →   +12 Thank you to make sure exact "problem number and contest duration" before 2 days .
 » 5 months ago, # |   +8 Tight! Tight! Tight! Yeah!!!
 » 5 months ago, # |   +17 Thank you and Codeforces team for making our quarantine enjoyable and productive.
 » 5 months ago, # |   +456
•  » » 5 months ago, # ^ |   -34 Finally, you got some upvotes. :)
•  » » » 5 months ago, # ^ |   +24 Еnvy silently! ))
•  » » » » 5 months ago, # ^ | ← Rev. 2 →   -49 [Deleted]
 » 5 months ago, # |   +11 Thanks for it "** I have tried to make short statements and strong pretests**"
 » 5 months ago, # | ← Rev. 2 →   +144 Announcement: ...You, for participating!Everyone :
 » 5 months ago, # |   0 ""I have tried to make short statements and strong pretests."" ..Happy to see this..i think there have not any confused word like "simultaneously" (in the previous contest) ..GL everyone.
 » 5 months ago, # |   +20 I appreciate your efforts for personally writing this post yoursef :)
 » 5 months ago, # |   +45 Thanks a lot. But please make the problem statements clear enough and straightforward. Best Wishes <3
 » 5 months ago, # |   -10 Thanks, Everyone who was prepared this round for us.
 » 5 months ago, # |   +54 "You, for participating!" It felt so good to hear this.
 » 5 months ago, # |   +7 i have a good feel about the contest ,I feel this contest have a nice ideas and problems.
 » 5 months ago, # |   +54 FieryPhoenix OFZ
 » 5 months ago, # |   -14 Hope no "simultaneously" to meant "at anytime".
 » 5 months ago, # |   +116 Hey!I'm sorry if this has been asked before — but I'm just curious about why rounds are becoming longer on average? There seem to be a few rounds these days which are either 5 questions in 2 hours or 6 questions in 2 hours and 30 minutes. A short while back, rounds seemed to be 6 questions in 2 hours on average. Are authors and coordinators looking to make rounds harder, or maybe more implementation based? Or is this to account for more participants in some way?Thanks!
 » 5 months ago, # | ← Rev. 6 →   0 It feels like I'm participating in the contest after ages
 » 5 months ago, # | ← Rev. 2 →   -113 Nothing matters anymore
•  » » 5 months ago, # ^ |   -8 make codeforces, not coronaforces
•  » » 5 months ago, # ^ | ← Rev. 3 →   -45
 » 5 months ago, # |   +16 I want to be Master !!! rp++
•  » » 5 months ago, # ^ | ← Rev. 3 →   0 bilibil"l"?!
 » 5 months ago, # | ← Rev. 3 →   -92
•  » » 5 months ago, # ^ |   +45 Please stop re-posting memes from last contests. Get something new man! We're bored of this.
•  » » » 5 months ago, # ^ |   -32 n btw this is not the memes site
•  » » » » 5 months ago, # ^ |   0 many of them put memes here it is just a matter of fun bro nothing like that dont take it too seriously...!
 » 5 months ago, # |   +253
 » 5 months ago, # |   +12 Hi, I am new to this platform and would like to know more about the contest. Details such as — what parameters will affect my ratings?
•  » » 5 months ago, # ^ |   +1 For your site rating, the system is ELO based. For the rating for any particular contest, the problems are worth different amounts, and you also get less points for a problem as time goes on.You can look up the FAQ.
 » 5 months ago, # |   +4 Very happy to hear "short statements and strong pretests". This contest is how all contests should be. Also, one very very good thing is this guy thanks the participants , a new start on Codeforces . This practice should be carried on.
•  » » 5 months ago, # ^ |   -7 He didn’t thank the participators for first time. He also thanked participators in his last round. You can check this
 » 5 months ago, # |   -7 Scoring distribution please. :)
•  » » 5 months ago, # ^ |   -7 Score distribution generally ppublish just before the contest start
•  » » 5 months ago, # ^ |   +51 It's up now :)
•  » » » 5 months ago, # ^ |   +15 Its great to see score distribution one day before the contest.
 » 5 months ago, # | ← Rev. 2 →   -78 Deleted.............
 » 5 months ago, # |   0 Hope for a balanced contest (hope so, because of balance score distribution)
 » 5 months ago, # |   +104 As someone who tested this round, I can guarantee that FieryPhoenix's English is very good, and there are no major grammatical mistakes in the task statements!
•  » » 5 months ago, # ^ |   +3 I'm curious. Given the situation, you would have found "major grammatical mistakes in the task statements". What would you have posted here instead?
•  » » » 5 months ago, # ^ |   0 As a tester I would have fixed them before the contest even began by pointing them out to the contest writer :)
•  » » 5 months ago, # ^ |   +1 I would be very shocked if his English was bad, considering he is in United States.
 » 5 months ago, # |   +93
•  » » 5 months ago, # ^ |   -8 Maybe you should hope that it does come in this contest itself! :/
•  » » 5 months ago, # ^ |   0 Always happens ya basha ):
 » 5 months ago, # |   -66 Can u make it 30 or 60 minutes earlier?
•  » » 5 months ago, # ^ |   -37 When you ask for an earlier contest and all you got was downvotes
 » 5 months ago, # |   0 here another pupil thanks for this rouund
 » 5 months ago, # |   -28 Do anybody here like long story type statements? I enjoy them, when the story has a character. The story of the character of one problem is related to the previous one.
•  » » 5 months ago, # ^ |   +31 I don't mind a story and sometimes I enjoy reading them. All I'm asking for, though, is clarity of the task. I think it is better for short contests like codeforces ones (2 to 2.5 hours) to have brief statements, as not every participant is equally educated to English.
•  » » 5 months ago, # ^ |   +71 Go read novel. Dont waste time here.
 » 5 months ago, # |   0 Hopes to see some new problems starting with COWs on codeforces!
 » 5 months ago, # |   -9 "You, for participating!"I love this. Thank you for treating us in a good way.
 » 5 months ago, # |   +45
 » 5 months ago, # | ← Rev. 3 →   0 Take love from deep of my heart <3. You guys awesome.
 » 5 months ago, # |   0 Contest after 5 days. So much excited. Good Luck everyone. <3
 » 5 months ago, # |   0 Want to be pupil for the 1st time after so many struggle. Just 14 need..GL & HF .
 » 5 months ago, # |   0 Contest and Ramadan ... Both are enjoyable...
 » 5 months ago, # |   0 Hope this contest can be nice! Good luck for everyone!!
 » 5 months ago, # | ← Rev. 2 →   +22 500 — 1000 — 1500 — 2000 — 2500 — 3000After a long time, the score distribution is an arithmetic sequence! Really looking forward to this round!
•  » » 5 months ago, # ^ |   +27 Finally, well-balanced round
•  » » » 5 months ago, # ^ |   +12 I cannot disagree more with this statement. Div2B was the hardest Div2B I have seen in a while.
•  » » » » 5 months ago, # ^ |   0 I agree it was a bit harder than usual but I really liked the actual problem.
•  » » » » 5 months ago, # ^ |   0 at the same time,it's the easiest div2D i ever met
•  » » 5 months ago, # ^ |   0 yes brother. Agree with you <3
 » 5 months ago, # |   0 Thank's for your efforts :) hope to enjoy it, good luck next ones
 » 5 months ago, # |   +27 Oh, It's May Day Contest.
•  » » 5 months ago, # ^ |   +15 and my rating sends mayday signal
•  » » » 5 months ago, # ^ |   0 And no airstrip around to land :(
 » 5 months ago, # |   0 i wish i would become specialist today. but not sure about it. need rank under 4500 or mostly i do bad in div2 haha.
 » 5 months ago, # | ← Rev. 2 →   -11 Almost 20k participants... It's amazing!!Upd. 20k+..sensationally
 » 5 months ago, # |   +26 For the first time, I noticed in contest announcement to include You, for participating in thanks giving list. Liked it. You forgot to include yourself in the list. Thanks for your efforts to make the round!
 » 5 months ago, # | ← Rev. 2 →   -11 Nice score distribution.
 » 5 months ago, # |   0 here scoring distribution is standard, does that mean there is no difference between the guy who solves faster than other. And how does the ranking is decided? is there any penalty
•  » » 5 months ago, # ^ |   0 maybe 50 points per wrong submission
•  » » 5 months ago, # ^ |   +1 As time passes, each problem is worth less points. So there is a difference between the guy who solves faster than the other.
•  » » » 5 months ago, # ^ |   0 yeah, thanks
 » 5 months ago, # |   +38 Rip rating
 » 5 months ago, # |   +5 How to solve C and D?
•  » » 5 months ago, # ^ | ← Rev. 3 →   +14 DLet's make an array $A$, where $a_i$ denotes the increase in mass on day $i$. The answer can be easily restored from it, as exactly $A_i - A_{i - 1}$ bacteria split between nights $i - 1$ and $i$.At most, on day $i$, twice as much mass will be gained, compared to day $i - 1$ (in case every bacterium splits in two).At least, the increase will be the same as on the previous day.Now forget for a while that there is a lower bound on mass increase (surely we can't kill existing bacteria) and greedily construct the abovementioned array (always splitting all bacteria) such that its sum equals $n - 1$ (we already have $1$ mass).It will look like $2, 4, 8, ..., 2^k, x$, where $x$ can be anything from $0$ to $2^{k + 1}$. If it is larger/equal than $2^k$, then we're good to go. Otherwise we can just sort it, obtaining a valid sequence!
•  » » » 5 months ago, # ^ |   0 Sorry, I feel like, Yes, did all of the above. And then, what should I print as ans?
•  » » » » 5 months ago, # ^ |   0 Second sentence
•  » » 5 months ago, # ^ |   +3 For c i used some observations. first sort the given string s. then try to distribute initial k characters for i = 0 to k-1. the remaining string rem = s[k:n] if rem contains more than one distinct char then it is better to add this whole rem to k-1 th string.Then ans = s[k-1] + remif rem only contains only one distinct char(like aaa , bbbbb) distribute those n-k characters equally , (n-k)%k will be remained after that. if (n-k)%k !=0 we need to add an extra character to ans then ans = s[k-1] + rem[0] * ((n-k)/k + ( (n-k)%k == 0 ? 0 :1)) ) note : "a" *3 = "aaa"
 » 5 months ago, # |   +8 what was the TestCase 10 in E
 » 5 months ago, # |   +29 Great round and great problems! Your contests are brilliant! I solved AD. I feel D and C should've been swapped. D felt a lot easier tbh. I found D easier than B, which I wasn't able to solve (and wasted more than 40 mins on) :( I was clueless on C after pondering and drawing stuff for 20-ish minutes. Read D, and happened to solve it in about 15-20 mins.Also, does anyone know how to hack solutions? I locked my problems at around 2:20 and tried viewing other solutions for D, however, none of them loaded. Is it just my internet or servers being slow or am I doing something wrong?
•  » » 5 months ago, # ^ |   0 Acc to me C was easy. You just need to know "aac" is greater than "aaaac" and bingo :)
•  » » » 5 months ago, # ^ |   0 I wasn't able to think of what I'd do to implement it. I was thinking along the lines:Sort the string. Calculate the number of times the first character in the sorted string appears. If it is greater or equal to $k$, print substr(1, n - 1); If $K == 1$, print the sorted string. Otherwise, print the k'th character. This didn't work, but I would've probable solved it if I gave it some more thought. The thing is, I like to read all problems during the contest time, and so I happened to read D. My luck kicked in when I realised I've solved a similar problem in the past, and went straight into implementation. Good luck in future contests!
 » 5 months ago, # |   +25 Video Editorials for today's C and DCDEnjoy watching!
•  » » 5 months ago, # ^ |   0 orz, thanks for the videos!
 » 5 months ago, # |   -8 good ones
 » 5 months ago, # | ← Rev. 2 →   +10 How do you do C? I tried doing casework but miserably failed )):D was pretty easy for placement though (for those who are more math-minded)
•  » » 5 months ago, # ^ |   +12 How did you did B it was a lot difficult
•  » » » 5 months ago, # ^ |   0 I was stucked in pretest 4 of B? Otherwise simple greedy approach to make a sequence of distinct elements and print it n times and also checking if the distinct string made is possible by the value of k(s.length()<=k).
•  » » 5 months ago, # ^ |   +5 For c i used some observations. first sort the given string s. then try to distribute initial k characters for i = 0 to k-1. the remaining string rem = s[k:n] if rem contains more than one distinct char then it is better to add this whole rem to k-1 th string.Then ans = s[k-1] + remif rem only contains only one distinct char(like aaa , bbbbb) distribute those n-k characters equally , (n-k)%k will be remained after that. if (n-k)%k !=0 we need to add an extra character to ans then ans = s[k-1] + rem[0] * ((n-k)/k + ( (n-k)%k == 0 ? 0 :1)) )note : "a" *3 = "aaa"
 » 5 months ago, # |   +23 Why so much tight time limits for problem E. My code kept giving TLE on test case 33.
•  » » 5 months ago, # ^ | ← Rev. 2 →   +16 I guess they intended to optimise max computation :/UPDWait, what? 78729467 78794202 I thought that n*k was the intended solution when I wrote this comment. But yes, indeed harsh time limit.
•  » » 5 months ago, # ^ |   0 I guess you forgot to update DP and it calculates each of them too many times.
•  » » » 5 months ago, # ^ |   0 I am updating the dp, notice that I have used ll &ans=dp[ind][red] and not ll ans=dp[ind][red].
•  » » » » 5 months ago, # ^ | ← Rev. 2 →   +9 Oh right. My solution is very close to yours but not with recursive functions but with true DP.
•  » » 5 months ago, # ^ |   +40 All of our solutions ran very fast, but I didn't expect a recursive approach. Sorry about that.
•  » » » 5 months ago, # ^ |   0 So according to your estimate, recursive approach is how much slower than iterative one? this will help me in future.
•  » » » » 5 months ago, # ^ |   +37 In general, recursion has a higher constant factor than iteration.
•  » » » » 5 months ago, # ^ |   +37 There are some cases when recursive works faster since it calculates fewer states. Anyway, I think the main problem is long long arrays with many modulo operations
•  » » 5 months ago, # ^ |   +17 Why would you use long longs everywhere and not submit in C++64? Long long stuff run a lot faster in C++64.
•  » » » 5 months ago, # ^ |   0 I didn't notice that there is a C++ 64 also. I am changing my default to C++64 immediately. thanks for pointing out!
•  » » 5 months ago, # ^ |   +8 I think your problem are the multiple divisions and modulo operations over k. Since you are keeping red and blue to be modulo k, one easy (and actually faster) way to do this is using an if: if (something >= k) something -= k, ans++; I'm doing exactly what you are doing (actually added a second loop over the blue ones just to be sure) and still passing with the recursive approach.
•  » » » 5 months ago, # ^ |   0 Got AC with the optimization you used. Thanks.
 » 5 months ago, # |   +15 Not sure what I am doing wrong, but my rating is going down rapidly. Nice problems anyway, thanks for that.
 » 5 months ago, # | ← Rev. 2 →   +32 WOW Nice problems man, specially E and F, both were very tricky and interesting, C was too tricky in my opinion but still it was very nice.
 » 5 months ago, # |   +20 Am I the only one who felt D was easier than C? lol
•  » » 5 months ago, # ^ |   +8 I wasn't even able to solve C but I solved D after around 20 mins of reading it :(
•  » » » 5 months ago, # ^ |   +7 Yeah, me too lol. D was more like a math question that I've happened to solve in the past. Speedforced it in under 20 mins.
•  » » 5 months ago, # ^ | ← Rev. 3 →   +7 +1Problem C was more complex to write code
 » 5 months ago, # |   +21 Great problem!
 » 5 months ago, # |   +36 Problem B was tough, I could not debug C on time. Nice contest.
 » 5 months ago, # |   +52 Excellent contest Fieryphoenix! Problem D was especially unique and creative. Enjoyed :)
 » 5 months ago, # |   +43 Solved D for the first time in a contest and in the last 30 sec, coudn't be happier :')
 » 5 months ago, # |   +16 It was the toughest B for me
•  » » 5 months ago, # ^ | ← Rev. 2 →   +6 All you have to do in problem B is that check if total number of different numbers in array is less than or equal to k if this inequality holds means answer exist and take k numbers from array(include each number atleast once) and print them repeatedly n times .
 » 5 months ago, # | ← Rev. 2 →   +14 Was I the only one who felt it was most difficult B ever and toughest C to implement?
•  » » 5 months ago, # ^ |   +11 C was a ton of casework, but if you write out all the cases, then the code is actually not too bad. https://codeforces.com/contest/1348/submission/78683019
•  » » » 5 months ago, # ^ |   +1 nice implementation.thanks for sharing! Good takeaways for me!
•  » » » 5 months ago, # ^ |   +5 You can get away with just 3 cases.First sort the string.Case 1: The bottom K letters are not all the same. Then the answer is simply the K-th letter from the bottom. Example:s="aabcccdddd", K=3 => answer is "b".Case 2: The bottom K letters are all the same, but the rest of the letters aren't. Then the answer is a single copy of the bottom letter, followed by the entire top N-K letters. Example: s="aaabcccdddd", K=3 => answer is "abcccdddd".Case 3: The bottom K letters are all the same, and the top N-K letters are all the same. Then the answer is a single copy of the bottom letter, followed by (N-1)/K copies of the top letter. Example: s="aaabbbbbbbb", K=3 => answer is "abbb".
•  » » » » 5 months ago, # ^ |   +1 thanks for this wonderful explanation!
 » 5 months ago, # |   0 Is ans for $D$ is highest bit set in $n$
•  » » 5 months ago, # ^ |   0 This is what I had: int days = Long.numberOfTrailingZeros(Long.highestOneBit(n));
•  » » » 5 months ago, # ^ |   0 How to construct the answer
•  » » » » 5 months ago, # ^ |   0 What I did is have sum = 1, and count = 1. Important thing to notice is that you can only increase count from 0 to count. Greedily choose highest count you can without going over the limit N across the remaining days which can be calculated with binary search or a simple formula: long here = Math.min(count, (n — sum) / (days — i) — count);Then it is easy as count += here sum += countThen print out here for the current day.Do this for every i from 0 to days — 1
 » 5 months ago, # |   -10 Earlier round of the same setter FieryPheonix was better than this round Round 621
 » 5 months ago, # |   +9 Superfast Editorial thanks
 » 5 months ago, # |   0 This was a really tough contest!
 » 5 months ago, # |   +11 I wish the pretests were strong. I was able to solve A,B,C for the first time in Div 2. Thanks for the amazing contest.
 » 5 months ago, # |   +1 What is test case 2 of problem C??
 » 5 months ago, # |   +27 Great contest,,short problem statements that were easy to understand..
 » 5 months ago, # |   +2 :(
 » 5 months ago, # |   0 I made so many silly mistakes, and it caused me a lot of penalties, it is not happening the first time, can anyone plz suggest me some way or something to reduce these mistakes
 » 5 months ago, # |   0 Could you please help me why I got TLE in problem Cmy submission:: https://codeforces.com/contest/1348/submission/78744306
 » 5 months ago, # | ← Rev. 2 →   0 This is my 11th contest. I love codefores❤❤❤
•  » » 5 months ago, # ^ |   +3 This is your 11th contest.
 » 5 months ago, # | ← Rev. 2 →   0 _**Looking for incresing Contribution as usual!! :) **_
 » 5 months ago, # |   +9 Awesome contest..LOVED D....Tricky E...took a lot of time figuring out that it was actually a dp question but it was too late... :-(
 » 5 months ago, # |   -35 This was literally the shittiest contest I ever participated in. Such types of problems are not expected to come in contests NO algorithms ONLY if-else based problems which are of no use at all.
•  » » 5 months ago, # ^ |   0 Those if else case works are important for logic building. You can't be better by knowing only algorithms without case works.
•  » » 5 months ago, # ^ |   +4 Algorithms are tools,which help us solve problems.Logic is the real thing that every contest should have.What will you, and eventually,everyone say if the next contest is Algorithm-only, logicless?
•  » » » 5 months ago, # ^ |   +4 So you mean algorithm based problems are illogical ??
•  » » » » 5 months ago, # ^ | ← Rev. 4 →   +4 Algorithms-only:If you meet these Algorithms-only Problems, you'll immediately know which algorithm to use.(Sorry, I should declare that)Yes, they aren't absolutely illogical, but they only require a little logicThey should be used as upsolving problems, instead of contest problems.UPD: I know that you didn't perform well in this contest. It doesn't matter. Everyone, including me, had some bad performance in the past.Try to perform well next time. If you are not good at logic-thinking, just practice. Practice makes perfect
•  » » 5 months ago, # ^ |   0 I feel you brother, bad results are disapointing. But at least you solved B. Welcome back to green!
•  » » 5 months ago, # ^ |   +7 How could you solve problems D-E-F with if-else based solutions?
•  » » 5 months ago, # ^ |   0 Logical,Mathematical,DS and algorithmic questions are the essence of competitive coding.Just because there was no DP, graphs or other known algorithmic questions in the first 4 doesn't mean its bad.
 » 5 months ago, # |   +5 I really appreciate that you used BABA in your examples, and also using Phoenix(i know its related to your name) reminds me CSGO's Shattered Web Operation, so i felt at home when solving the problems :D, thank you.
 » 5 months ago, # |   +19 My greedy solution in E got AC. Most probably it shouldn't pass but I'm not able to break it.
•  » » 5 months ago, # ^ |   +71 Hacked it
 » 5 months ago, # |   0 Why does using Priority queue gives TLE on test case 32 in problem C ? isn't it O(nlogn) which should pass ?Link to Submission
 » 5 months ago, # |   +3 Systests are pretty fast this time.It took less than 45 mins :D
 » 5 months ago, # |   +15 **This is my solution for A **78678522
•  » » 5 months ago, # ^ |   0 Well done
 » 5 months ago, # |   +21 Everything was perfect in this contest! Thank you!
 » 5 months ago, # |   0 editorial is out at super fast speed :) nice
 » 5 months ago, # |   0 Dare Elder brothers and Sisters, please suggest me, which languageis best among, Java and C++.
•  » » 5 months ago, # ^ |   0 for CP , C++
•  » » 5 months ago, # ^ |   0 For programming purpose, I think C++ is best!!
•  » » 5 months ago, # ^ |   +8 Maybe first try English?
 » 5 months ago, # |   0 Figured Out Logic for B that we need to print array of {1,2,3..,k} n times but for case of impossibility what i'm doing actually is find out the maximum value if it is >k then print -1 while the thing that needed to be considered is find out number of different if those are > k then pattern is not possible . here the line which has tons of meaning is "you may print element which are not in original array". (p.s:- those who have done same mistake i have song for you guys BENEE — Supalonely ft. Gus Dapperton enjoy.)
 » 5 months ago, # |   0 In problem C why this code gives TLE on test 8? 78747924
 » 5 months ago, # |   0 What is the meaning of this "checker log : wrong answer Unexpected EOF in the participants output" ? I am getting this in TC2 for problem C. My submission : Here
•  » » 5 months ago, # ^ | ← Rev. 3 →   +3 Means the validator/checker is expecting more lines(i.e. more test cases or more data, whatever) but your input/output doesn't have any more.
•  » » » 5 months ago, # ^ |   0 Yes thank you very much. I used return in testcases instead of continue, I just realized that(T_T).
 » 5 months ago, # |   +1 same code 78704677 compiler: GNU C++17 verdict: WA78705346 compiler: GNU C++17 (64) verdict: ACBut why??
•  » » 5 months ago, # ^ |   0 I too wanna know why this happens, last contest i saw someone shared solution that got AC in g++17(64) and tle in g++17.
 » 5 months ago, # |   0 Editorial published so fast.. Thanks.
 » 5 months ago, # |   0 Did the edge between divisions change? I didn't see participants with rating 1900-2100 in official standings of Div2 round before.
•  » » 5 months ago, # ^ |   +4 when div.1 and div.2 both round happens then only 1900-2100 rated participants belongs to div.1 .
•  » » » 5 months ago, # ^ |   +1 Got it, thank you!
•  » » 5 months ago, # ^ |   0 In Div2 only contests (even Educational Rounds actually) are rated for Candidate Masters. When it is a Div2+Div1 contest, then Div1 is rated for Candidate Masters.
 » 5 months ago, # | ← Rev. 2 →   +6 I have a problem in the judge of my submission to problem C:This is my submission inside the contest:It gives me TLE in test case 25After the contest I try to copy and paste the code and submit it again here https://codeforces.com/contest/1348/submission/78751136It got accepted that mean it should be accepted in the contest tooWhat is the problem of this?
•  » » 5 months ago, # ^ |   0 It sometimes happens that when you run your code multiple times, it takes different times to run.
•  » » » 5 months ago, # ^ |   0 So it will not be rejudged ? Or their is no solution now?
•  » » » » 5 months ago, # ^ |   0 Nop, it wont get rejudged 90% of times.
•  » » » » » 5 months ago, # ^ | ← Rev. 3 →   0 I also try it here:787537977875376978753708and still got accepted how could I ask for rejudge ?
•  » » » » » » 5 months ago, # ^ |   +4 I don't know, FieryPhoenix would answer here probable :).
•  » » 5 months ago, # ^ |   +4 There are so many submissions on system test stage, the server have lower performance than normal case. And you code runs 1996ms, it's too close 2000Ms. So your code get TLE on systen test stage.
•  » » » 5 months ago, # ^ |   0 I also try it here:787537977875376978753708and still got accepted how could I ask for rejudge ?
•  » » » » 5 months ago, # ^ |   0 I'm sorry to say that i think you will get TLE again on rejuding stage. And it almost impossible rejudge the contest again!
•  » » » » » 5 months ago, # ^ |   0 :''D
•  » » 5 months ago, # ^ |   0 I mean 1996 ms for a time limit of 2000ms is goddamn close
•  » » » 5 months ago, # ^ |   0 Okay but also 1996 is accepted case.
 » 5 months ago, # |   -28 I've just recived this message from SystemВнимание!Ваше решение 78721802 по задаче 1348A значительным образом совпадает с решениями других участников и находится в группе одинаковых решений try11/78721329, Hadiayoub7/78721802. Такое совпадение является явным нарушением правил. Отметим, что непреднамеренное утечка тоже является нарушением. Например, не следует пользоваться ideone.com с настройками по умолчанию (публичным доступом к вашему коду). Если вы имеете неоспоримые доказательства, что совпадение произошло по причине использования общего источника, опубликованного до соревнования, то напишите комментарий к посту о раунде со всеми деталями. Подробнее можно прочитать по ссылке http://codeforces.com/blog/entry/8790. Такое нарушение правил может являться основанием для блокировки вашего аккаунта или других штрафных санкций. В случае повторения нарушений, ваш аккаунт может быть заблокирован.and these two accounts belong to me, should I do something about it ?
•  » » 5 months ago, # ^ |   +25 Multiple accounts are not allowed mate.
•  » » 5 months ago, # ^ |   +20 You should read contest rules carefully! The rules are as flows!The registration confirms that you: have read the contest rules by the links http://codeforces.com/blog/entry/456 and http://codeforces.com/blog/entry/4088 will not violate the rules described on http://codeforces.com/blog/entry/456 and/or http://codeforces.com/blog/entry/4088 will not communicate with other participants, share ideas of solutions and hacks will not use third-party code, except stated in http://codeforces.com/blog/entry/8790 will not attempt to deliberately destabilize the testing process and try to hack the contest system in any form will not use multiple accounts and will take part in the contest using your personal and the single account.
 » 5 months ago, # |   0 C++17: 78738413 gives TLE C++17(64 bit) :78750670 AC Both of them are same code. Why this happens?
•  » » 5 months ago, # ^ |   0 Because C++17(64 bit) is somehow a little faster.
 » 5 months ago, # |   0 Learned Many things today....Thank you
 » 5 months ago, # |   0 Nice contest :)
 » 5 months ago, # |   0 Great round, thanks for super-fast rating updates and so well written prompt editorials(with easy to understand commented code)
 » 5 months ago, # |   0 great round and thank you very much.. but there are small note: There is an error in the ratings of people who have moved to a higher level as it showing that they are at the same level as they were
 » 5 months ago, # |   +5 Thankyou for hardwork. As it was said, short and clear statements. A lot of fun to solve. And become candidate master !!
 » 5 months ago, # |   +14 A: 78733229 and A: 78665020 B: 78733627 and B: 78706022C: 78734137 and C: 78731691 are exactly same.Handle name is also almost same and submission time clearly indicates it's a cheating.Please have a look FieryPhoenix
•  » » 5 months ago, # ^ |   -9 submission times indicate that submissions of the first account within the contest, while all submissions of the second account outside the contest time, so I do not think this is a cheating.
•  » » » 5 months ago, # ^ |   +1 It was a 2 hour 30 min contest. So i think all the submission was during contest time.
•  » » » » 5 months ago, # ^ |   0 That's right, I apologize, I forgot that the contest duration is 2:30
•  » » 5 months ago, # ^ |   0 acts of cheating like this harms the rating of others
 » 5 months ago, # |   +1 i passed problem E,but still have questionsi used $O(n^3)$ dp at first and got tle on pretest 33then i used a list to optmize and passedis the complexity right after i optimize the algorithm?78735089 here's my solution
•  » » 5 months ago, # ^ |   0 You can ask in Luogu Discuss Area, some nice guys can help you there.
•  » » » 5 months ago, # ^ |   0 I think he definetely know that since he's a Master lol
•  » » 5 months ago, # ^ | ← Rev. 3 →   +10 Me too,I tried a $O(nm^2)$ dp and got TLE.And the next morning I changed my code and used less long long and % and it passed.Update:Fixed some stupid grammar mistakes.
 » 5 months ago, # |   +29 Have anyone noticed that the checker comment in this round is "ok good job (xx test cases)"? Phoenix even makes the checker comment enjoyable:)
 » 5 months ago, # |   0 In my opinion, problem B was more difficult than most 2B's, but it is also one of the more interesting ones.
 » 5 months ago, # |   0 Thanks for the really nice set of problems.
 » 5 months ago, # |   0 ConstructiveForces
 » 5 months ago, # |   0 My O(n^3) dp isn't passing, getting WA in test 33. 78795957Do we need something like O(n^3/x) to pass. And how can I optimize this?
 » 5 months ago, # |   -24 Meh stupid codeforces nerds are on downvote frenzy this quarantine, better stay away from comments section y'all
 » 5 months ago, # |   -22 Problem C is not clear. It can have many solution but it is accepting only unique answers.
•  » » 5 months ago, # ^ |   +17 There are multiple optimal ways to distribute the letters but the answer resulting from the distribution is always unique.
•  » » » 5 months ago, # ^ |   -8 Can you please explain more, I am not able to figure out how.
 » 5 months ago, # | ← Rev. 2 →   +18 Did anyone notice that there are hidden messages in test 31 of problem C? Contents of test 319 8 2 chefspam 11 7 monkeyeight 8 2 vcubingx 6 1 amazed 4 4 hebs 8 1 arolakiv 9 7 hidavidhu 33 33 gosubtovcubingxheneedssubscribers 7 4 hiimbad (vcubingx is a YouTube channel. I do not know about the meaning of the other text in this testcase. Can FieryPhoenix provide an explanation?)
•  » » 5 months ago, # ^ |   +34 Haha, this is just an Easter Egg relating to some of my friends. Nice catch :)
•  » » » 5 months ago, # ^ |   +34 FieryPhoenix O.OFiery and the boys!
•  » » » 5 months ago, # ^ |   +37 :|
•  » » 5 months ago, # ^ |   +33 vcubingx is a YouTube channelHey, that's me! The rest of the people are IRL friends of FieryPhoenix and I.
•  » » 5 months ago, # ^ |   +26 Hello, I am secret message.
•  » » 5 months ago, # ^ |   +25 Unfortunately 8 isn't a letter :(