I uploaded 2020 Petrozavodsk Winter Camp, Jagiellonian U Contest to the CF Gym.
The problemset was used in 2020 Petrozavodsk Winter Camp, and North America Programming Camp 2020. Both ghosts are in scoreboard, so it's a good opportunity to test your skills.
In the version used in PtzCamp and NAPC, problem K had a weak test and the model solution failed in my simple handcrafted tests. I just added that test, and changed the problem limit leniently to allow model solution to pass. I guess this made the problem much easier now.
Thanks to the problemsetters (I don't know who are them). Enjoy!
Seems like the link to the Editorial is just the problem statements.
Fixed, thanks
Very interesting ... is the mystery figuring out where the problem statements disappeared to?
I can only see the titles and time limits.
You're welcome.
For G, is it provable that there exists some permutation such that the lines will not cross given all xi, yi's are distinct, or are the test cases weak? (My solution here simply tries every permutation and outputs one which works)
Any one with the smallest sum of distances, for example
In the sample test of problem J, why the answer for the second query is "YES"? I don't see any way to move from $$$(8, 1, 1)$$$ to $$$(3, 2, 2)$$$.
$$$(8,1,1)\rightarrow (3,1,1)\rightarrow (3,1,2)\rightarrow (3,2,2)$$$
Oh right... Guess that I just can't wrap my head around 3D problem.
Can problem H use min cost flow to solve?