fcspartakm's blog

Codeforces Round #293 (Div. 2)
By fcspartakm, 10 years ago, translation, In English

Hello, Codeforces!

I'd like to invite you to Codeforces Round #293 (Div. 2). It will be held on Tuesday, February 24 at 19:30 MSK and as usual Div. 1 participants are invited to join out of competition.

Great thanks to Maxim Akhmedov (Zlobober) for helping me preparing the contest, to Maria Belova (Delinur) for translating the statements into English, to Mike Mirzayanov (MikeMirzayanov) for the great Polygon platform and ideas of some problems and to my dear friends Pavel Kholkin (HolkinPV), Arthur Svechnikov (ikar) and Vitaliy Kudasov (kuviman) for writing solutions.

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

UPD Score distribution will be 500-1000-1500-2000-2500-2500. Good luck everyone!

UPD2 Competition completed! Thank you all!

UPD3 You can find editorial here.

UPD4 Congratulations to the winners!

  1. urkkvr145
  2. 0o00oo0o000oo00o
  3. sorry_t0nyukuk
  4. NgocHai
  5. GintokiSakata
  • Vote: I like it
  • +184
  • Vote: I do not like it

Comments Comments (82)
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10 years ago, # |
← Rev. 2   Vote: I like it +12 Vote: I do not like it

a little bit late announcement but i hope system testing won't be late :D

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10 years ago, # |
  Vote: I like it +5 Vote: I do not like it

Unusual Round... Hope something fun!!! Best of luck to everybody!!

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10 years ago, # |
  Vote: I like it 0 Vote: I do not like it

I told to my boss that i would participate on a online contest on codeforces and he was agree, life it's beautiful :P

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    10 years ago, # ^ |
      Vote: I like it -31 Vote: I do not like it

    still specialist in 35 contest... u need upsolve problems

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      10 years ago, # ^ |
        Vote: I like it +5 Vote: I do not like it

      He has very busy schedule due to job. Atleast he finds time to participate. That makes him a great person

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10 years ago, # |
  Vote: I like it 0 Vote: I do not like it

It's special contest to celebrate CF's 5 year anniversary? :)

Codeforces has had an excellent start, and I'm sure it will grow and continue to become better in the future!

On behalf of everyone, thank you for this wonderful site!

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    10 years ago, # ^ |
      Vote: I like it +18 Vote: I do not like it

    Actually it is not a special anniversary contest. But I'm personally helped with ideas for the problems. I hope you will like them :-)

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10 years ago, # |
  Vote: I like it 0 Vote: I do not like it

oh!I hope I won't be wrong in the system testing!

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10 years ago, # |
  Vote: I like it 0 Vote: I do not like it

Good luck to everyone! May the best coder win!!!

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10 years ago, # |
  Vote: I like it 0 Vote: I do not like it

your looks handsome and thanks for prepare a wonderful contest maybe. GL&HF.

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10 years ago, # |
  Vote: I like it 0 Vote: I do not like it

I'm gonna be the contest King, and win this round :D
say hello to the one who is gonna get the first place(me)!

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    10 years ago, # ^ |
      Vote: I like it +34 Vote: I do not like it

    I_Hate_This_Type_Of_Coders

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    10 years ago, # ^ |
      Vote: I like it 0 Vote: I do not like it

    I think you're going to forget about becoming the winner for jenabe_haghani(Haghani), since he is registered for this contest.

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      10 years ago, # ^ |
        Vote: I like it 0 Vote: I do not like it

      You know Haghani is gonna become an unofficial participant so he can't officially win the round

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10 years ago, # |
← Rev. 2   Vote: I like it 0 Vote: I do not like it

You can use this tag :)

"Happy birthday codeforces"

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10 years ago, # |
← Rev. 2   Vote: I like it -38 Vote: I do not like it

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10 years ago, # |
  Vote: I like it 0 Vote: I do not like it

Best of luck to everybody

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10 years ago, # |
  Vote: I like it 0 Vote: I do not like it

Most hacks in Problem A ever.... So weak pretests...

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10 years ago, # |
  Vote: I like it +1 Vote: I do not like it

Great! I just love those contests full of hacks :D

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10 years ago, # |
  Vote: I like it -44 Vote: I do not like it

very Bad contest

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10 years ago, # |
  Vote: I like it +9 Vote: I do not like it

I wonder why there isn't syntax highlighting in the source when they are displayed for hacking. That would make it a bit easier to understand the already horribly obfuscated codes people submit here.

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10 years ago, # |
  Vote: I like it +1 Vote: I do not like it

Problem A was awesome :) . Got my locked code hacked, but still got 700 points from hacks :D

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10 years ago, # |
  Vote: I like it 0 Vote: I do not like it

Thanks for the fast editorial!

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10 years ago, # |
  Vote: I like it 0 Vote: I do not like it

Many bugs in problem E, I did ternary search in every sequence of '?', someone else? but I couldn't finish this is my code Your text to link here...

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10 years ago, # |
← Rev. 2   Vote: I like it 0 Vote: I do not like it

Very-very funny contest :) even though I didn't get good result.

Problem A: I solved it <10mins, and I solve B <1h 20m.

But when I see the standing, I'm very-very embrassed... there is TOO MANY hacks in Prob A.

So, I think: "I should try hacks, too!" and I tried hacks and got 2 success and 2 fails.

And I checked my rank is > 900... then I tried to solve C, and I solved it in 02:22 (8 mins remain..)

I think my C solution is veryveryvery complicated.. I can't understand my algorithm fully. (a bit of luck? :> )

It was very funny and interesting contest. Thanks for contest problem makers :)

P.S. I'm sooo nervous for system testing :<

P.S 2 — The fastest systest ever! Wow..! I just got rank 1232, and only B correct. I didn't think of long long in Prob C...:<<

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    10 years ago, # ^ |
      Vote: I like it +1 Vote: I do not like it

    Did you use long long for C? Some people in my room forgot about it and they got hacked by me :D

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      10 years ago, # ^ |
        Vote: I like it 0 Vote: I do not like it

      No, I didn't.. but is it essential? why..?

      If you're right, then I will lose about 600 points... goodbye my blue nickname :<

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      10 years ago, # ^ |
        Vote: I like it 0 Vote: I do not like it

      I just checked my logic is completely right (by editorial)

      but I didn't use longlong.... omg

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      10 years ago, # ^ |
        Vote: I like it 0 Vote: I do not like it

      I'm very sad :< My critical mistake..... Because of my critical mistake, I lost my blue nickname

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        10 years ago, # ^ |
          Vote: I like it 0 Vote: I do not like it

        Now you'll never forget to use long long, and get it back next contest :P

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          10 years ago, # ^ |
          ← Rev. 2   Vote: I like it +1 Vote: I do not like it

          Yeah, I will... and I should..

          I submitted the new solution using long long (nothing changed except longlong), and I got AC....

          • I protected my blue! yeah! (1601 -> 1526)
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        10 years ago, # ^ |
          Vote: I like it +1 Vote: I do not like it

        Do not be sad! Next time you won't forget about this and you'll hack those who will forget it :D

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      10 years ago, # ^ |
        Vote: I like it +1 Vote: I do not like it

      Same mistake. :'(

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10 years ago, # |
  Vote: I like it 0 Vote: I do not like it

This contest was awesome! Thanks!

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10 years ago, # |
  Vote: I like it 0 Vote: I do not like it

first time ever was hacked, A problem(

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10 years ago, # |
  Vote: I like it +11 Vote: I do not like it

Fastest systest ever!

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

Wow, this is the first time I ever seen system test can go that fast, about 1min

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10 years ago, # |
← Rev. 2   Vote: I like it 0 Vote: I do not like it

The winner solved 4 problems and 27 hacks, and 2nd contestant solved 5 problems and +8 and -5 hacks.. this is already very rare situation, but additionally, solvers of 6 problems are in 7th place.. very very very rare contest..

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10 years ago, # |
  Vote: I like it 0 Vote: I do not like it

http://mirror.codeforces.com/contest/518/hacks/137892/test I think I was hacked against rules. In C statement is written: "Each integer from 1 to n occurs exactly once among a_i." How it is possible and what to do?

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    10 years ago, # ^ |
      Vote: I like it 0 Vote: I do not like it

    Don't see what's wrong with the test case?

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    10 years ago, # ^ |
      Vote: I like it 0 Vote: I do not like it

    Each integer from 1 to n still occurs exactly once among "a_i". You can have any values in b_i.

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    10 years ago, # ^ |
      Vote: I like it 0 Vote: I do not like it

    I hacked your solution with this case. There is nothing against the rules, you can open an app multiple times :P Your solution has an undefined behavior in this case :P

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10 years ago, # |
  Vote: I like it +2 Vote: I do not like it

Thank you very much for a wonderful contest!

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10 years ago, # |
  Vote: I like it +11 Vote: I do not like it

Who do you think has the best implementation for the last problem? I just bruteforced it with a bunch of functions that are almost identical — 10005221

Nice contest, by the way, although it wasn't hard.

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

Finally, purple after 65 contests! Thanks for this round. System testing was also quick.

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

thanks fcspartakm ,finally your contest made me purple :)

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10 years ago, # |
  Vote: I like it 0 Vote: I do not like it

Could somebody help me with DIV 2 B ? I failed at 30 system test http://mirror.codeforces.com/contest/518/submission/9990527 , but input isn't visible

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    10 years ago, # ^ |
    ← Rev. 2   Vote: I like it 0 Vote: I do not like it

    Change the type of small[] and big[] from char to int then got accepted. In Java, char is 16-bit. 16-bit's maximum is 65535, lower then the input size(2*10^5).

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10 years ago, # |
  Vote: I like it +11 Vote: I do not like it

I'll just leave it here

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10 years ago, # |
← Rev. 2   Vote: I like it 0 Vote: I do not like it

Am I the only one who sees nothing over here: http://mirror.codeforces.com/contest/518/hacks ?

UPD: And it's fixed now.

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10 years ago, # |
  Vote: I like it +9 Vote: I do not like it

Very interesting

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10 years ago, # |
  Vote: I like it 0 Vote: I do not like it

Could authors of this contest kindly share test #24 for the problem E? Thanks in advance.

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10 years ago, # |
  Vote: I like it +12 Vote: I do not like it

Finally, the number of submissions reached 10000000!

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10 years ago, # |
  Vote: I like it -22 Vote: I do not like it

I'm the champion of this round.

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