https://mirror.codeforces.com/blog/entry/137621?#comment-1233118 Is this means that intended solution for I2 is broken? If so, how do we treat about this is it wholey unrated?

If there were various issues with the contest's problems, can the system test still be started?

for G, splay tree: TLE Red black tree: AC(500ms)

don't know why :(

does case like

3

1 7

4 1

9 5

intentionaly removed? I can't imagine these case doesn't appear if case was randomly created. If it was on purpose, I can't believe power of multi-testcase any more...

so sad... does usual SRM's remain?

I used log-exp trick, though get WA on test 21

Is div1-A's sample2 made by tourist himself?? I'm astounded him using Japanese internet meme how did he know that??(I know that it's well-known in Chinese...)

Isn't there any alternative way to distribute problem statements?

E, nice problem, it's ok. Though isn't the time limit and memory limit too strict? I know you want not to make O(Nlog^2 N) (or maybe O(NlogN) which I don't know how to), but 2 sec is enough to and there is no reason to make memory limit 256MB.

Thanks for preparing for the contest and I'm very interested for the contest.　By the way, couldn't it have announced a little earlier?

If I remember correctly, this contest's schedule was added to the calender three days ago. As div1 contests are not abundant, I try to adjust my schedules as much as possible since the date has been added. Actually, three days ago is too late to make adjustments. Ofcourse I understand there are several reasons why you can't give us notice, but can it be a little quicker? As div1 contests are valuable, we contestants want to participate in as many as possible.

I think it's just one aspect. There are still many solutions which actually have a hack case, though passed the system test. Killed solution is just one part of it. (But "Failed System Test" has large effect to himself, it's taken bigger than it actually is)

Preventing all wrong solution is unrealistic, and most of as notice it. A few contest site has hacking system (as far as I know, only topcoder?), it still works. Do we really need to get rid of ALL wrong codes?

In the first place, do we need hacking system?

Now, earning points by hacking is largely based on luck. Most hacks are made on easy problems. Because of room system, submittion for hard problems are really few. So even if we found some strong test to hack some sort of wrong codes, it is rarely applicable.

So, most of hack points are made to tiny miss or luckily passed O(N^2) solutions, which are easy to hack if we can find it. This mostly depends on luck which mean "how many roommates participate" and "how many has submitted hackable solution". Is this really fair?

Ofcourse others hacking points won't affect much to yourself's standings or performance, so it was not a big deal. Though, this system won't show one's ability precisely, much more from luck. If we have some problem of this system, removing it makes sense.

Too hard to hack something like this B :( Is accepting copying submission during the contest has any problem?

I also think that low-rated can create hard problems, though it's still true that low-rated are hard to estimate and manage the detail of the problem as they have a small amount of experience to solve similar difficulty problems.

If div1 are redundant, setting a rate limit may be one measures, but...

does eng Tutorial of G,H gonna be available later or only Chinese are given?

I'm Curious about whether the round was unrated or not if the problem wasn't copied, just a coincidence. In my opinion, the situation that someone wrote the comment of the same problem's detail during the contest is fatal, and worth to be unrated. (this has no difference from writing the solution of the problem during the contest)

Is there a way to cancel upvote/downvote and revote to the other one?

Do someone succeed to find div1-E on the internet with your own power?

I want to know the method and searching technique for the future

Is there any editorial? Or plz someone give me solution of I.

Thanks to this contest, I had become LGM!!!

appreciate very very much for writer and tester!

isn't MNULS's testcase too weak?

the greedy solution: go to the largest B. once B = A + k, it'll be that all the way.

will pass the test, but 5340 93 can hack this solution. (correct:61, greedy:62)

I'm surprised to wake up and hear this news *_* btw, will my rate will be recalculated??

use sparse table. improves to O(n log n).

friends!!!!!

120609085 my sweet O(NQ) solution has passed... :)

thanks for all!!! I'll try to upsolve it.

is there editorial of GRAND and CLAMPWAY? I have no idea besides centroid decomposition which takes O(nlog^2 n).

why G was so big constraint? My O(NlogN) solution get TLE (TT)

They say that "we'll renew web arena", "we'll support C++17" but never does.

so, you mean that the problems are still remain correctly even if it is mathematicaly wrong but can perdict it from some kind of fuzzy "common sense"?

I don't so much care about whethere it is unrated or not, but the dealing with this issue to say "if youre high rated and found it strange, report it" is a question mark(as statement makes a sense without the order constraint, I have no idea but somewhere of my code is wrong.)

Problems should have been established only by the problem itself. not depening on something lile "common sense".I hope the future rounds wont repeat and I can help it by reporting.

I have one nice idea for preventing: let's totally get rid of STORIES :)

want to take a glance at the issues on C.

https://mirror.codeforces.com/blog/entry/90915?#comment-797718

I've chosen the solution same as yours and get "Wrong answer on test 2."

As allowing the "non lexicographical order" operations just extend the valid operations and the fact that "all testcases has solution", our solution have give a answer.

but the verdict was "Wrong Answer" so I guess the output checker was checking is it lexicographical order or not.

If the output checker was taking into consideration but forgotten to write in the statement, it's a so so FATAL MISS!!!!

yes, the addition was not just the description. it fundamentally changed the problem.

It's not only "hard to read" or "hard to understand" but it's broken as a problem. I can't say it's enough to be unrated but should take into account whether making this round unrated or not. MikeMirzayanov Vladik

Does problem C's initial statement form a proper problem? Before the sentence 'then the sequence of items should always remain increasing in lexicographical order' was added, I couldn't found the operations like

1

2

1.1

are invalid from the initial statement.

The announcement of the addition of previous sentence was so late that it's hard to say that the impact of this problem was little.(actually, I've use so long time to debug my code which was doing something like the previous operation)

Hope for the appropriate response.

SO SO SOOOO waiting for C++17.

can't we upsolve it?

many of the solutions of F can be hacked with the case

6 7
1 2
1 3
1 4
1 5
4 5
4 6
5 6

there seems other hack case for other participants which couldn't hack with this case too. Is the testcases prepared for the system test strong enough??

sent by mistake

When are you planning to apply this new system? In particular, is it before next AGC(3/6)?

we may feel comfortable and easy to adapt if there is something like a testing round before the start of the new system.

Sorry for my mistake, I want to know about o(NK). My solution is O(nk + q) too, and considering that it can be more faster or not.

can D solve faster than O(N^2)? I've considered many ways to improve, but couldn't reach any efficient way.

I may have found F interesting, only if s was always "+*".

Happy for my first time to win in div2! XD

maybe you're right, but I'm not so brave or strong enough to forgo may-be hints in front of me :(

"most of the problem have alternative solutions" — agree. though, the information which this comment provides is not only "the existence of the alternative solution" but "the existence of alternative solution which is easy to come up with and worth to mention in editorial".

Do you still think this is no hint?

Do we really need these LONG LONG comments to all contributers and testers??

As some comments provide little hints, in some sense we're forced to read it and it's an annoying work for me. (like "inventing an alternative solution to one of the hard problems" is some kind of hint)

こるとんさんありがとう...(thank u,korton.)