Напоминание: в случае технических проблем любого характера, вы можете использовать m1.codeforces.com, m2.codeforces.com, m3.codeforces.com. ×

Блог пользователя hmehta

Автор hmehta, 3 года назад, По-английски

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

  • Проголосовать: нравится
  • +47
  • Проголосовать: не нравится

»
3 года назад, # |
  Проголосовать: нравится +22 Проголосовать: не нравится

Gentle Reminder:: Match begins in 5 mins

»
3 года назад, # |
  Проголосовать: нравится +33 Проголосовать: не нравится

Notorious coincidence: https://codeforces.com/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.)

»
3 года назад, # |
  Проголосовать: нравится +36 Проголосовать: не нравится

Hard: 1479D - Odd Mineral Resource.

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

»
3 года назад, # |
  Проголосовать: нравится +18 Проголосовать: не нравится

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

Thanks.

»
3 года назад, # |
  Проголосовать: нравится +31 Проголосовать: не нравится

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.

  • »
    »
    3 года назад, # ^ |
      Проголосовать: нравится +17 Проголосовать: не нравится

    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.

    • »
      »
      »
      3 года назад, # ^ |
        Проголосовать: нравится +15 Проголосовать: не нравится

      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...)

  • »
    »
    3 года назад, # ^ |
      Проголосовать: нравится +37 Проголосовать: не нравится

    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.

    • »
      »
      »
      3 года назад, # ^ |
        Проголосовать: нравится -8 Проголосовать: не нравится

      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.

»
3 года назад, # |
  Проголосовать: нравится 0 Проголосовать: не нравится

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

  • »
    »
    3 года назад, # ^ |
      Проголосовать: нравится 0 Проголосовать: не нравится

    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.