hmehta's blog

Topcoder SRM 803
By hmehta, 4 years ago, In English

Single Round Match 803

Topcoder SRM 803 is scheduled to start at 11:00 UTC-4 on March 31, 2021. 

Registration is now open for the SRM in the Arena or Applet and closes at 10:55 UTC-4. The coding phase will start at 11:05 UTC-4, so make sure that you are all ready to go. Click here to what time it starts in your area

Thanks to Arpa for writing the problem set. Also, thanks to misof for testing and coordinating the round.

Please Note: As the final SRM of the stage, this is your last chance to earn points towards the TCO21 Regional Events qualification and TCO21 Online Stage 3.

Some Important Links:: Match Results (match results, rating changes, challenges, individual test case results), Problem Archive, Problem Writing, Algorithm Rankings, Editorials and Older Editorials(SRM 710 and before),

Best of luck!
- the Topcoder Team

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Comments Comments (15)
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4 years ago, # |
  Vote: I like it +22 Vote: I do not like it

Gentle Reminder:: Match begins in 5 mins

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4 years ago, # |
  Vote: I like it +33 Vote: I do not like it

Notorious coincidence: https://codeforces.net/contest/1479/problem/D

(Context: Div 1 1000 quickly reduces to this problem, which appeared on a CF round just a couple months back. I got AC by copying the editorial code with only some minor changes.)

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    4 years ago, # ^ |
      Vote: I like it +23 Vote: I do not like it

    Sorry about that, we were not aware of this problem. I try to keep up to date on as many of the serious contests as I can but my head also has only a finite capacity and I haven't seen this round at all.

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    4 years ago, # ^ |
      Vote: I like it -21 Vote: I do not like it

    I was not aware of this problem. Sorry.

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4 years ago, # |
  Vote: I like it +36 Vote: I do not like it

Hard: 1479D - Odd Mineral Resource.

Btw, I've spent 10 minutes debugging the generator because I copypasted rnd() function from Easy.

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

    Again, I was not aware of this problem. Sorry.

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

hmehta can you please make this contest available in the practice room.

Thanks.

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4 years ago, # |
  Vote: I like it +31 Vote: I do not like it

The test data for the whole set was prepared in less than 24 hours.

https://docs.google.com/document/d/e/2PACX-1vS3WiQXwB4_oUSzgRhKvMW58dxZ7q8wpm-s17FveW6f-KGUIvTBRHIMKNS2UMVIRG7Ykwe3GH0Ijvu_/pub

I believe that this is not a good schedule for preparing a contest. (Why did you reveal this?) You wouldn't have made the stupid mistake in Div1 250 / Div2 1000 if you had prepared earlier.

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    4 years ago, # ^ |
      Vote: I like it +17 Vote: I do not like it

    Wait, I believe that sentence should be interpreted as it takes less than 24 hours to prepare the test data. Learn to read before you complain.

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      4 years ago, # ^ |
        Vote: I like it +15 Vote: I do not like it

      Ah, I see. Thank you for pointing it out. sorry that I was upset just after the contest. (I didn't complain about that sentence though...)

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    4 years ago, # ^ |
      Vote: I like it +37 Vote: I do not like it

    Arpa's comment is about test data, he has obviously worked on the problems more in advance. The issue that caused the clarification is about the statement, and I'm the one to (mostly) blame for that omission. I was making the final proofread of the statement and I completely missed that the sentence got lost — most likely while I was making some other edits to the statement. Selective blindness — sometimes you see what you expect to see and not what's there.

    Your point about making those edits earlier and the implied point about checking everything more carefully are absolutely correct and I apologize if anyone lost time by being confused.

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      4 years ago, # ^ |
        Vote: I like it -8 Vote: I do not like it

      Misof puts a lot of effort into contests as a contest coordinator. He proofread the statements and just this miss happened. I respect him as a great contest coordinator. You're good misof, orz.

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

Problem D1 Easy:

for (int i = 0; i < N; i++)
    for (int j = i + 1; j < N; j++)
	cnt += path[i][j] * path[j][i];
return cnt / 2;

Why we are dividing cnt by 2? I think we have already found all the possible paths from A to C then C to A that is cnt

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

    Consider the path A->B->C->D->A.
    We will count this path twice. Once while counting A->..->C->..->A. Also while counting B->..->D->..->B.

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