### E869120's blog

By E869120, 19 months ago,

Hello, everyone!

The 22nd Japanese Olympiad in Informatics (JOI 2022/2023) Final Round will be held from Sunday, February 12th, 10:00 UTC to Monday, February 13th, 10:00 UTC. The contest information is as follows:

• Contest duration: 4 hours (You can choose start time freely in 24-hour window)
• Max score for each task: 100 points
• Style: IOI-Style (There may be some partial scores)
• Problem Statement: Japanese & English

Note that since the contest ends at Monday, February 13th, 10:00 UTC, if you start the contest after Monday, February 13th, 06:00 UTC, the duration will be shorter than 4 hours.

The registration page will be announced 30 minutes before the contest starts. Details are available in the contest information page.

We welcome all participants. Good luck and have fun!

• +237

| Write comment?
 » 19 months ago, # |   +30 Bump
 » 19 months ago, # |   +34 Now the contest had ended. Thank you for your participation. Let's discuss the problem!
 » 19 months ago, # |   +54 Thanks for the contest!How to solve P5. Modern Machine?
•  » » 19 months ago, # ^ |   +84 Observation: at any time, the state can be described by $0\le L\le R\le N$, where the first $L$ letters are R, the last $N-R$ letters are B, while the other letters are the same as initial state.First consider subtask 5: $L=R=t$, note that pressing button $A$ would change $t$ into \$(t+[t
 » 19 months ago, # |   +8 What is the intended complexity of P3 Maze for 100 points?
•  » » 19 months ago, # ^ |   0 I found a O(RClogN) solution and a O(RC) solution.
•  » » » 19 months ago, # ^ |   0 My solution with RClog got only 84.Did you manage to get 100 with the RClog solution?
•  » » » » 19 months ago, # ^ |   0 My RClog got 94 and I tried to optimize some constants, but failed, so I coded RC solution.
•  » » » » 19 months ago, # ^ | ← Rev. 3 →   0 My RClogN solution got AC.
•  » » » » 19 months ago, # ^ |   +10 I used bitset instead of set and got AC. I'm surprised O(RC log R) doesn't pass, the log part is just one lower bound on a set. I guess the bottleneck is the erasing part, which can be done faster with bitset
 » 19 months ago, # |   +8 When will the upsolving stage be opened?
•  » » 19 months ago, # ^ |   +10 The analysis mode is now started. You can upsolve the problems in Contest Site until February 19th, 2023.
 » 19 months ago, # |   +91 This is how to solve C.
 » 5 weeks ago, # |   0 Sorry for necroposting. Can someone give a hint / explain the solition of 6. and 7. subtasks of P4 Cat Exercise?