So I will describe shortly what happened here.
The situation wasn’t like I didn’t see your messages, or ignored it.
I saw messages like check precision of your fft, are you sure of your fft? and I started panicking and ran big tests on brute force to confirm. After 20 minutes of running I saw that the test is correct so I was relieved. On the other hand a lot of people were getting 50 pts so I thought this is super normal and 1st subtask is ok. On polygon we had 4 solutions (2 fft,2 quadratic) for me and the setter and all were matching (same undefined behavior or I don’t know how is it called). On campus as well. On polygon you write input validator for every problem, and I did. Also, tester proof-read all of them. What I missed is, activating the validator for this problem (which would have detected the issue). I don’t know how i missed it, you should select a validator for each problem.
The test that people were failing on was like:
and there are only 9 testcases in the file
I am not an expert in undefined behavior to discuss the cases. Apparently, for a lot of people on the 10th case, the program was reading n = 0 and just terminating with no issues, and some other were keeping last value of n. For java an exception would be thrown I think. I am not sure why some c++ solutions were acting differently (maybe different input methods).
The fact that I didn’t activate the validator by just setting the field to “kthval.cpp” made this slip away. It would detect it because it will expect EOF
The result was ruining the contest for div1 which is something unfortunate. I would take a big part of the blame, and I feel like I owe the people a big apology. But neither me or the admin deserve that amount of negativity, we spent a lot of time to come up with the problems (which had a nice quality I think). It’s unfortunate that one mistake would turn all of it into nothing.
I just wanted to share this with the community, and my sincere apologies again. We as people make mistakes somtimes, and it’s not my first time setting problems in codechef (i also set a round before on CF) but this was the first time things go wrong.
As for the ratings, I have no idea and it’s up to admins.
The editorials will be posted in few hours I think.