KCOMPRES - Editorial

Why ?? I statement is update. But there is no announcement. Rule for problem setter should be made. I he wants to add a “.” also. Then he will be allowed to do so only after making an announcement on contest page.

Btw when this update was made ??

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My comment on Magic Set July’18 which nobody bothered to reply -

“Test Case 1 - Subsequences of [1,2] are [1],[2],[1,2] sym of all these is 6. (Divisible by 3). So answer should be 1? Is answer 0 correct?”

“When was “each” added in problem statement? And why is no announcement made after this change?” .

I remember reading statement multiple times because I got intution that this is what statement is asking. But each was not present there.

I came up with this kind of solution, too, but got some WAs for some unknown reason. Since I was using naive data structures in Haskell, I also got TLEs.

@koyaaniqatsi, you are correct. I have already mentioned in the editorial that the test case for small dataset was weak and the english statement was horrible. About 4 different people tested their solution during the preparation, but everyone got the same logic and everything looked ok then. Regarding question being removed or contest being unrated, please contact @admin or @mgch.

It is already mentioned in editorial that small testset was weak.

@buda It is already stated in editorial that english version of statement is wrong and thus the editorial apporach too. My intended task was exactly the same as @acmonster version of the statement, mentioned in editorial but it seems there was a huge fault here from my side.

There is a flaw in calculating colliding interval. You have considered that it can collide only once but there can be multiple places where it might collide. Eg : [1, 1, 1, 1, 1] and k = 2. All ranges are colliding but you don’t consider such cases. (Note, your solution will be correct for the case I provided, it is just to give you intuition where it might fail).

anyone? :0