MikeMirzayanov's blog

By MikeMirzayanov, 4 weeks ago, translation, In English,

Hello, Codeforces!

I'd like to invite you to Codeforces Round #436 (Div. 2). It'll be held on Monday, September 25 on 10:35 UTC and as usual Div. 1 participants can join out of competition. Note that round starts in the unusual time!

This round is held on the tasks of the school stage All-Russian Olympiad of Informatics 2017/2018 year in city Saratov. They were prepared by Perforator, MikeMirzayanov and fcspartakm. Many thanks to the testers: sdya и BledDest, and coordinators KAN and gritukan.

It will be a little unusual round — you will be given six problems and two hours to solve them.

Good luck and have fun!

Congratulations to winners!

Div. 2:

  1. ZJT_NOI2017_AK
  2. AngusRitossa
  3. Jha_The_ME_Coder
  4. cxh007
  5. Alexvsalex

Div. 1:

  1. Shik
  2. dreamoon
  3. black_horse2014
  4. orbitingflea
  5. NiroBC

Analysis is here.

 
 
 
 
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4 weeks ago, # |
  Vote: I like it +28 Vote: I do not like it

why it starts on that time ?? can't it just be as usual ??

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    4 weeks ago, # ^ |
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    At this time the Olympics in Saratov.

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    3 weeks ago, # ^ |
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    I only hope this round is friendly

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      3 weeks ago, # ^ |
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      I hope so. But surely I'll get every problem TLE or RE then.

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    3 weeks ago, # ^ |
      Vote: I like it +1 Vote: I do not like it

    Oh My God,, I completely missed the round not even a minute

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    3 weeks ago, # ^ |
    Rev. 2   Vote: I like it +5 Vote: I do not like it

    People from Far East are not able to participate in "usual" time for you. So this is this the one of few rounds in comfortable time for them. Please be patient :) P.S. But unusual time is in case of original olympiad time, to prevent cheating.

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4 weeks ago, # |
  Vote: I like it +22 Vote: I do not like it

Similar contest of last year : http://codeforces.com/contest/723

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4 weeks ago, # |
  Vote: I like it -6 Vote: I do not like it

unusual bad start time,just why???

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4 weeks ago, # |
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**It will be a little unusual round** — you will be given six problems and two hours to solve them what does it mean?

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    4 weeks ago, # ^ |
      Vote: I like it +206 Vote: I do not like it

    It means that you will be given six problems and two hours to solve them.

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      4 weeks ago, # ^ |
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      It will be a little unusual round I have problem with this part.

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        4 weeks ago, # ^ |
          Vote: I like it +58 Vote: I do not like it

        In usual round you have five problems, not six.

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4 weeks ago, # |
  Vote: I like it -10 Vote: I do not like it

Wooow 3 contest in 3 days

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4 weeks ago, # |
  Vote: I like it +9 Vote: I do not like it

Tough choice. Wake up at 3:30am or go to bed at 5:35am?

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    4 weeks ago, # ^ |
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    very nice time for china

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    4 weeks ago, # ^ |
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    another choice is no sleeping

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    3 weeks ago, # ^ |
      Vote: I like it +3 Vote: I do not like it

    Can't you do both?

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    3 weeks ago, # ^ |
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    we always stay up late to attend the test in summer,China.....

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      3 weeks ago, # ^ |
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      the best time for chinese

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        3 weeks ago, # ^ |
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        yes!:)

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          3 weeks ago, # ^ |
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          dalao哪里人?

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            3 weeks ago, # ^ |
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            please speak english

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              3 weeks ago, # ^ |
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              why we must speak english?i mean between two chinese

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                3 weeks ago, # ^ |
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                ok,i'm chinese,too.but most of the users are not chinese and they cannot understand you

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                  3 weeks ago, # ^ |
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                  i mean some others who look the communication between you two

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                  3 weeks ago, # ^ |
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                  fine,actually,we're both mogicians,my qq:2632812444

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                  3 weeks ago, # ^ |
                    Vote: I like it +6 Vote: I do not like it

                  Hey I don't think you should mh in cf(you know what I mean.) As this guy seems don't know what you are talking about.

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                  3 days ago, # ^ |
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                  GLGJSSY,QYHFBQZ

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                3 weeks ago, # ^ |
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                what,you are a magician .what do you mean

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4 weeks ago, # |
  Vote: I like it -6 Vote: I do not like it

Hope I can become candidate master after this round.

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    4 weeks ago, # ^ |
      Vote: I like it -38 Vote: I do not like it

    You won't. You will do badly and have 1833 rating right after.

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      4 weeks ago, # ^ |
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      Really? So when I can finally become candidate master?

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4 weeks ago, # |
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scoring ..??

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4 weeks ago, # |
  Vote: I like it -10 Vote: I do not like it

Russia's time is one o'clock in the afternoon, but for China is six o'clock in the afternoon. This is a good time for us, but it may be for some other people who need to stay up late at night or get up early in the morning.

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    3 weeks ago, # ^ |
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    What does that mean?

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      3 weeks ago, # ^ |
        Vote: I like it +4 Vote: I do not like it

      Well, in Most area in China, it's UTC+8. So it means if we want to join a contest which is held at six o' clock in evening in Moscow, it will be eleven'o clock in Beijing. In this case, most contests were hold in the midnight. To join it, we have to spend our sleeping time.

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4 weeks ago, # |
Rev. 4   Vote: I like it -10 Vote: I do not like it

.

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4 weeks ago, # |
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i hope clear and short statement.

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4 weeks ago, # |
  Vote: I like it -52 Vote: I do not like it

round will be rate or not ??

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4 weeks ago, # |
  Vote: I like it -11 Vote: I do not like it

Why so early. I'll be in school at this time(4

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    4 weeks ago, # ^ |
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    Don't go to school (if you don't have any important exam).

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3 weeks ago, # |
Rev. 2   Vote: I like it -7 Vote: I do not like it

I am a newbie and I wonder how to compare my rank profile to others in a picture? I need someone tell me plz. No down vote plz.

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3 weeks ago, # |
  Vote: I like it +14 Vote: I do not like it

This round is very kind for China :)

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    3 weeks ago, # ^ |
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    For Bangladesh too. It's going to be 4:30 at afternoon.

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      3 weeks ago, # ^ |
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      Ah! Really? I prefer the usual time. Why don't you?

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        3 weeks ago, # ^ |
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        I said 'kind' not "The Best".In some countries there is going to be a lot of trouble. I also prefer the usual time.

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    3 weeks ago, # ^ |
    Rev. 2   Vote: I like it +3 Vote: I do not like it

    Applese is so smart that he will solve all problems in this contest!

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3 weeks ago, # |
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I will take part in this,first time.

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3 weeks ago, # |
  Vote: I like it 0 Vote: I do not like it

I'm having a BED time participating this round...

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3 weeks ago, # |
  Vote: I like it -44 Vote: I do not like it

is it rated?

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3 weeks ago, # |
  Vote: I like it -13 Vote: I do not like it

Scoring?

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3 weeks ago, # |
  Vote: I like it +2 Vote: I do not like it

hope to be green :(

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    3 weeks ago, # ^ |
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    After System testing, not green yet but heading towards it.

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3 weeks ago, # |
  Vote: I like it 0 Vote: I do not like it

Can not hack

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3 weeks ago, # |
Rev. 2   Vote: I like it +49 Vote: I do not like it

3chenruiyangcsh, are you really a human???

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3 weeks ago, # |
  Vote: I like it +1 Vote: I do not like it

FAQ: Why at this time?

Answer: The same problems were used at the school stage All-Russian Olympiad of Informatics, so it's important that it's participants shouldn't participate in this round, because they had the same problems 4.5 hours earlier.

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3 weeks ago, # |
  Vote: I like it 0 Vote: I do not like it

nice pretests :)

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3 weeks ago, # |
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Hack page is not loading properly.

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3 weeks ago, # |
Rev. 5   Vote: I like it +15 Vote: I do not like it

RIP E. :(

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3 weeks ago, # |
  Vote: I like it 0 Vote: I do not like it

I have a question on Problem A, why answer of this is not yes?

4 2 1 1 3 First one will choose 2 & second one will choose 1, then first one will choose 3. So both of them will have same numbers of card.

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3 weeks ago, # |
  Vote: I like it +8 Vote: I do not like it

Kept getting Wrong Answer on pretest 3, Problem E. Any hints?

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    3 weeks ago, # ^ |
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    I think it's just some small random test. I got wa on test 3 because I didn't maintain parent array correctly.

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    3 weeks ago, # ^ |
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    well pretests are weak i guess i sorted the values by d before dp and another one in my room sorted by t both pretest passed

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    3 weeks ago, # ^ |
      Vote: I like it +3 Vote: I do not like it

    This test help me:

    5
    1 2000 1
    1 2000 4
    1 2 19
    1 4 18
    1 3 17
    
    Ans:
    59
    5
    3 5 4 1 2
    
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      3 weeks ago, # ^ |
      Rev. 2   Vote: I like it 0 Vote: I do not like it

      The question's language is so bad :( I explicitly sorted :( WA

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        3 weeks ago, # ^ |
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        I took dp[i][j] to be the min time required to get value of j from first i items. If I dont sort according to deadline I get wrong ans, but if I do I get right answer. I dont know how sorting is helping. Can u pls tell?

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          3 weeks ago, # ^ |
          Rev. 6   Vote: I like it 0 Vote: I do not like it

          Firstly, I mentioned sorting for the final part, when we have to print the answer.

          Coming to your question, sorting with deadline is necessary because if you don't, you might miss out some optimal combinations.

          Try running your code on mentioned test and realise:

          2

          2 5 3

          2 3 5

          ans:

          8

          2

          2 1

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3 weeks ago, # |
  Vote: I like it +3 Vote: I do not like it

Missed a stupid edge case in problem C,ACed in the last 7 minutes ;/ Also guys,how to solve problem D ? I thought about it for a full hour,came up with 3 non working greedy solutions,

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    3 weeks ago, # ^ |
      Vote: I like it +4 Vote: I do not like it

    D seemed ad hoc, I got AC in pretests. The number of changes is just n-number of unique integers in the input. And change the first duplicate to 1 and then the second duplicate to the next smallest possible element that's not in the array till now and fill like this. I hope it doesn't fail O.O

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      3 weeks ago, # ^ |
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      wont your approach fail at test case number one, because the first duplicate is "3" at i = 1,so you will replace that 3 with "1" as "1" is not in the initial array, Next at i = 2, we get a[i] = 2 which is also a duplicate,so we will replace that with 4, yours should give answer 1 4 2 3 in this case.. I think I dont clearly understand your approach,please elaborate,thanks!!

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        3 weeks ago, # ^ |
        Rev. 2   Vote: I like it +1 Vote: I do not like it

        I passed the system tests yay! So yeah, I told a bit wrong. What I did was....

        Let the element to be replaced(in pace of a[i]) be cnt; if current element(2 in this case) is less than cnt, then I check if I have left any 2 before, if I have then I will change current 2 to cnt or else I will leave it and go to the next index and mark 2 as done. Code here: http://codeforces.com/contest/864/submission/30711359

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3 weeks ago, # |
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Pretest 6 problem C?

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3 weeks ago, # |
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Guys, I am new here at Codeforces, can anyone plz tell where i'll find the editorials to the contest problems ?

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    3 weeks ago, # ^ |
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    Editorials will be avialable soon , link will be given in thi post after update. Also you can view editorial directly from problem page once they are released. Usually editorials are avialable with few hours .

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    3 weeks ago, # ^ |
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    its takes time.

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3 weeks ago, # |
Rev. 2   Vote: I like it +10 Vote: I do not like it

Problem C

01:40:22 Pretests passed [pretests] → 30719776

01:53:58 Problem locked

01:55:26 Hacked by lyllyl

:( :( :(

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3 weeks ago, # |
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C — https://pastebin.com/nE1gS3Wd

Why WA at pretest 6?

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3 weeks ago, # |
  Vote: I like it -7 Vote: I do not like it

CF — Predictor are it`s working with any one ??

i want to know my expected rate :( :(

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3 weeks ago, # |
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Why do I like this contest so much?)

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3 weeks ago, # |
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Hack for C: 10 8 6 2 Answer : 2

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How to solve the problem E?

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    3 weeks ago, # ^ |
    Rev. 2   Vote: I like it 0 Vote: I do not like it

    Sort items by deadline:

    dp[j][t] — maximum value you can get, when you select from first j items, when you are at time t.

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      3 weeks ago, # ^ |
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      How would you go about recovering the indices of the chosen items?

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        3 weeks ago, # ^ |
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        Remember what are you doing in the state (if it is invalid — i.e. t >= d[i], move to dp(i,d[i]-1)). Then you can either take item i or do not take it and move to dp(i-1,t). When you recover the soultion, just follow the same decisions.

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      3 weeks ago, # ^ |
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      I took dp[i][j] to be the min time required to get value of j from first i items. If I dont sort according to deadline I get wrong ans, but if I do I get right answer. I dont know how sorting is helping. Can u pls tell?

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3 weeks ago, # |
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I noticed that this guy: ILIAz is accessing uninitialized variable in case the ans = 0: http://codeforces.com/contest/864/submission/30720468

Unfortunately my hack with 1 item did not work...

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3 weeks ago, # |
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How do we do F?can anyone tell me please?

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3 weeks ago, # |
Rev. 3   Vote: I like it 0 Vote: I do not like it

@admin I submitted E about a minute before the end of the contest. I straightaway got WA on pretest 1 which works fine on my system. Moreover, my submission can not be seen on the standings page. Please fix this. KAN

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    3 weeks ago, # ^ |
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    Submissions not passing the first test are not shown on the standings and are not counted in penalty.

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3 weeks ago, # |
  Vote: I like it +15 Vote: I do not like it

When you were about to solve E first time in your life but then you get WA because you wrote x instead of a[x][3]

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    3 weeks ago, # ^ |
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    I myself did a silly mistake , corrected it , as i went for submit -->>> contest ends :-(

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3 weeks ago, # |
  Vote: I like it -18 Vote: I do not like it

fuck shit man

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3 weeks ago, # |
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For problem D,I'd like to know how my method is wrong...Thank you in advance.

Firstly count the unnecessary number in the sequence,(for example 2 2 then one of the 2 is not necessary ,it must be replaced by other number) and then set i =1 loop in range[1,n],when find a number which has appeared 2 or more times in the sequence then try to replace it,but if even the smallest number which haven't come up in the sequence is larger than this unnecessary number then we don't replace it;otherwise,replace the unnecessary number with the smallest number which haven't came up yet.

And for those number still not appear in the sequence(let them be a set),set i=n down to 1 loop,then perform the replace operation from the bigger to lower in the set then output the sequence

And I got WA on test 8,until the ending of the contest I didn't pass pretests and just lose the scores of the unsuccessful submissions and got a terrible standing ...As I'm not perform well in several current contests I don't want this bad condition continue I'm so sad...

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    3 weeks ago, # ^ |
    Rev. 5   Vote: I like it +3 Vote: I do not like it

    I tried the same approach as you and I cannot come with a test that makes my solution fail. Let's wait until tests are visible... :(

    upd: wrong answer 3183rd numbers differ — expected: '3390', found: '125991'

    I think it is better to continue thinking about it XD

    upd2: try this one

    5
    1 2 2 4 4
    

    Note that the missing numbers are 3 and 5. On the forward iteration we will replace the first 4 with our 3, and on the backwards one we will replace the second 2 with our 5. This will leave the array 1 2 5 3 4. However, note that we can get the array 1 2 3 4 5 by changing two numbers, too.

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      3 weeks ago, # ^ |
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      Ouch...I got it now...Thank you(you are so clever...I didn't find such test cases before reading your comment by myself...

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3 weeks ago, # |
  Vote: I like it +13 Vote: I do not like it

Me After seeing superfast system tests Image

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    3 weeks ago, # ^ |
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    looks like you haven't been participating in cf rounds since more than a month bcoz these days its fast.

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3 weeks ago, # |
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Solved 3. Good for me or else i would have gone to depression.

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3 weeks ago, # |
  Vote: I like it +30 Vote: I do not like it

How to solve F?

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    3 weeks ago, # ^ |
      Vote: I like it +14 Vote: I do not like it

    Consider the arrays of short ints reach[3001][3001] and nex[3001][3001][13]. Define

    • reach[i][j] = 1 implies there exists a path from i to j. Easily generated with DFS.
    • nex[i][j][k] is the 2k + 1-th node on the optimal path from i to j,  or infinity if it does not exist. First generate nex[i][j][0] from reach,  and then generate nex[i][j][k + 1] from the values of nex[i][j][k].

    For a query (s, t, k) first check nex[s][t][12] and nex[s][t][0] to see if there is an infinite cycle, or a path does not exist. If none of these are equal to infinity, we can just compute the k-th node on the path in a similar manner to LCA.

    Of course, it is easier to just compute the answers in an offline fashion.

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      3 weeks ago, # ^ |
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      I just read your code. I was amazed to see you use "short" while I received MLE using "int" in the contest.:( However,it seems that the time limit is so loose that I passed the problem by only storing nex[3001][3001][6] and brutishly use nex[x][y][5] when k is too large. Maybe it looks like a sqrt deviding.:)30738221

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    3 weeks ago, # ^ |
      Vote: I like it +5 Vote: I do not like it

    A solution which probably uses a bit less memory than Benq's.

    After reading the input, sort adjacency lists by the endpoint node: this way doing a DFS traversal will result in ideal paths.

    Group all queries by the starting node. We'll answer each group separately with a separate DFS that starts from the starting node.

    Doing the traversal maintain some additional data structures:

    • A stack of the nodes on the current path (append the current node to it at the beginning of the recursive function and remove at the end).
    • An array to tell if a node is currently on the stack (in current path). We can reuse the same array that we use to mark whether the node has been visited.
    • Unordered set of nodes that form a loop: whenever we find an edge to a node that is currently on the stack, we add it to this set; before we end analyzing the node we remove it from this set (at the same time as we remove it from the stack).

    Whenever we reach a node which is an end point in any of the queries with our starting node and we did not compute the answers for them yet:

    • if the set is not empty, set the answer to -1 (we know that there is a loop that we can use to continue making the path to this node lexicographically smaller indefinitely);
    • otherwise, set the kth element of the stack as an answer for each of the corresponding queries.
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3 weeks ago, # |
  Vote: I like it -15 Vote: I do not like it

Is this round rated?

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3 weeks ago, # |
Rev. 2   Vote: I like it 0 Vote: I do not like it

KAN MikeMirzayanov My code is giving error on problem D. (Exit code is -1073741819). Solution It is giving error on this test case: 2 2 2 I have checked it on my pc and also at custom invocation at Codeforces it is working fine. UPD:Sorry, there was some minor error, I have fixed now.

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    3 weeks ago, # ^ |
      Vote: I like it 0 Vote: I do not like it

    I am also getting the same error on test case 4. Input: 6 5 5 5 6 4 6

    however on my pc it is giving correct output

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3 weeks ago, # |
Rev. 5   Vote: I like it 0 Vote: I do not like it

Sorry, I've just made a mistake.

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3 weeks ago, # |
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Could someone explain me the test case for F?

7 7 5
1 2
2 3
1 3
3 4
4 5
5 3
4 6
1 4 2 // 2
2 6 1 // -1
1 7 3 // -1
1 3 2 // 2
1 3 5 // -1

Here query(1, 4, 2) == 2. However, there is no ideal path from 1 to 4 (1-2-3-4 > 1-2-3-1-2-3-4 > ...).

Where am I wrong?

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3 weeks ago, # |
  Vote: I like it +9 Vote: I do not like it

Is it real to solve problem E by random-based solution?

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3 weeks ago, # |
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Cant load the pages . Is sys test over?

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How to solve problem C?

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    3 weeks ago, # ^ |
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    Greedy + Simulation. Suppose you are at 0, if you can go to 0--->a---->f without refueling go, otherwise go to f first refuel and carry on. Vice versa for a to 0. Carefully implement it.

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      3 weeks ago, # ^ |
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      Thanks!!

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      3 weeks ago, # ^ |
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      It is giving wrong output on testcase 7. Can you help what corner case I am missing?

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        3 weeks ago, # ^ |
          Vote: I like it 0 Vote: I do not like it

        You can see the test case on which your code is giving wrong answer. BTW, your condition for -1 is wrong. It should be if b < max(f,a-f) return -1.

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    3 weeks ago, # ^ |
    Rev. 2   Vote: I like it +3 Vote: I do not like it

    One way to solve problem C is using Dynamic Programming approach.

    Think on this function F( i, j ) = maximum amount of gas that I can have if I have had i journeys using j times gas station before.

    See my code for more details: 30708352

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3 weeks ago, # |
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Why is the cf predictor not showing today's round ?

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3 weeks ago, # |
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Rating update is taking so long. It seems it is compensating for fast system testing.

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3 weeks ago, # |
  Vote: I like it +19 Vote: I do not like it

No mention of winners :( . Don't know I will ever come under 5 or not again :(

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3 weeks ago, # |
Rev. 2   Vote: I like it +15 Vote: I do not like it

Lately, I'm constant af...

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3 weeks ago, # |
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Thank you god for helping me not make systest failing bugs today. :)

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3 weeks ago, # |
  Vote: I like it +16 Vote: I do not like it

It seems that there is only one people (me) confused by the definition of "lexicographical order" in Problem C.

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    3 weeks ago, # ^ |
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    Sorry...I mean Problem D...(will I get lots of downvotes? scared:(

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3 weeks ago, # |
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I got hacked at a problem today. Can someone explain how hacking a problem works and how can I hack someone? Also, when will the editorial be posted?

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3 weeks ago, # |
  Vote: I like it +7 Vote: I do not like it

Finally, I became candidate master!!!

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3 weeks ago, # |
Rev. 4   Vote: I like it 0 Vote: I do not like it

I'm blocked on something silly and am unable to figure out whats wrong. Would be great if any of you could help! For problem E, In this submission, I have clearly sorted my vector before printing it. Yet, it somehow prints a non-sorted sequence. (Check verdict for test case 3)

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    3 weeks ago, # ^ |
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    Test case 3) Participant's output 1 2 4 5 6 7 8 9 looks sorted to me

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    3 weeks ago, # ^ |
      Vote: I like it +11 Vote: I do not like it

    deathsurgeon

    "In the third line print m distinct integers — numbers of the saved items in the order Polycarp saves them."

    The answer isn't necessarily sorted x)

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    3 weeks ago, # ^ |
      Vote: I like it +3 Vote: I do not like it

    Firstly, I misinterpreted the question. Secondly, I also got confused between "output" and "answer" in submission. Ahh, I'm getting old at this :/ Anyways, thanks NMouad21!

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3 weeks ago, # |
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Anyone got the idea of problem F test 13 query 24?

I saw many people failing on it... (including me...)

I was wondering if the algorithm was incorrect...

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    3 weeks ago, # ^ |
      Vote: I like it +3 Vote: I do not like it

    That could be because of incorrect algorithm. At least mine fails thereat.

    Test your solution with

    3 2 1
    1 2
    1 3
    1 3 2
    

    It should output 3

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      3 weeks ago, # ^ |
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      Oops, my solution passed this test...

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      3 weeks ago, # ^ |
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      I found a data that can cause me WA now

      7 7 1
      3 4
      4 5
      5 1
      5 2
      1 6
      6 1
      2 7
      3 7 5
      

      Thanks for your help!

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3 weeks ago, # |
Rev. 4   Vote: I like it +1 Vote: I do not like it

in problem 864E — Fire

I can't understand why it's right to sort the input by d and then calculate the answer with dp ,, t is also affecting the answer as t can be large and d small so i should take this value after other values with large d ?

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    3 weeks ago, # ^ |
      Vote: I like it +12 Vote: I do not like it

    Consider any two items. If in the optimal answer, I am only going to take one of them, then their relative ordering doesn't matter.

    But if both of them are in my optimal answer, then which one would you take first? It makes sense to take the one which is ending first (i.e. has a smaller d value) than the one which is ending later (i.e. has a higher d value).

    Since if you first took the one which is ending later, and then took the one which is ending earlier, then you can also do the inverse, i.e. take the one which is ending earlier and then take the one which is ending later.

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    3 weeks ago, # ^ |
      Vote: I like it +6 Vote: I do not like it

    Its about the order of choosing of course its better to choose the items with less d first so they wont be expired

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    3 weeks ago, # ^ |
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    Imagine that d[i] + 1 is a moment when explosion hits i-th item. And DP approach here is just a process of caching recursive brute-force which would traverse items in increasing order of d[i] because it optimizes order preserving O(n!) bruteforce and overcomes 0-1 preserving O(2^n) bruteforce (there is no other simple bruteforces I've thinked about here).

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3 weeks ago, # |
  Vote: I like it -11 Vote: I do not like it

Is there going to be a tutorial?

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3 weeks ago, # |
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Why my program not work in task B. In my computer its working good! http://codeforces.com/contest/864/submission/3075

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3 weeks ago, # |
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It seems Tutorial link under contest is wrong

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3 weeks ago, # |
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Kindly add the correct tutorial link to the contest material section. It is opening Manthan's editorial link.

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3 weeks ago, # |
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Please hack my submission on problem D(Although someone helped me with my earlier idea about this problem right after contest but I came up eith a new method and passed the case he provided but got WA on test8...)I really don't know why this method got wrong answer...submission30755521 Thank you in advance.

The main idea I came up is to count the times every numbers appear int the sequence,and maintain a set containing all the missing numbers didn't come up in the sequence yet,and set a loop from 1 to n just to do such operation: if the number appear in this position is counted more than once,then replace it with the smallest number which didn't came up yet and decrease the counter of the original number in this position by 1(You will say this must be wrong but please go on reading...)After doing this we set a loop from 1 to n again and if find a position that the new number I just filled in it is larger than the original number in there before,then replace this number to the original number,push the replaced number(the bigger one) into a vector which contains all the numbers that must be replaced to more left position,at the same time maintain a vector to push back the last position of the original number in this sequence(it means that the bigger number will be put in sequence with the index as big as possible),then sort the position and the replaced numbers,and fill these pool numbers in these positions one by one.(Sorry for my bad English and description...

Thank you again for hacking this solution....

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    3 weeks ago, # ^ |
      Vote: I like it 0 Vote: I do not like it

    try this case

    7
    6 1 1 6 1 1 6
    

    Your output

    5
    2 1 3 5 4 7 6
    

    Answer

    5
    2 1 3 4 5 7 6
    

    What's more...I failed to analyze the code so no solution or reason to be provided. :(

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      3 weeks ago, # ^ |
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      Thank you very much...

      And now I think the reason why this code got wrong answer is just because in this method the sequence maybe have some missing numbers already in some positions which they are not going to be. (What a bad solution I created...:-(

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2 weeks ago, # |
  Vote: I like it -10 Vote: I do not like it

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