I accidentally copied a CodeChef problem.
I was just made aware by satyam343 that 1996A - Legs somehow COINCIDES EXACTLY with FARMLEGS.
I had zero idea this problem even existed before right now. I even thought satyam343 was trolling and thought this problem was only published after my contest. It wasn't until I looked at submission dates that I noticed the problem was created more than three months ago... My problem was based on a mixture of middle-school word problems and me casually thinking of USACO cows.
Regarding how even the constraints are exactly the same: The constraints were initially $$$t \leq 10^5$$$ and $$$n \leq 2 \cdot 10^5$$$, but a tester did $$$O(tn)$$$ and still passed all test cases. Obviously, this is hackable, so we have to either decide to add a third test case with all tests being $$$2 \cdot 10^5$$$ or make $$$O(tn)$$$ comfortably pass. We didn't want to blow up queue even more, so we resorted to the latter option.
Anyways, this is way too funny, so I have to make a blog. This is also even more ironic since I advertised a CodeChef contest in the comments :skull:
I have like 2 total solves on codechef cut me some slack
I was made aware by IceKnight1093.
Actually G also appear in past TopCoder round https://community.topcoder.com/stat?c=problem_statement&pm=17083
F in gym with some tiny changes: https://mirror.codeforces.com/gym/100488/problem/H
Probably it's not an issue for div 3 to have cloned problems, these contests seem more like educational
Actually, (probably) the only problem in your round that didn't appear anywhere before is D.
For this reason, will the contest be unrated?
no.
Yep. Thanks for the reply, mate.
Not a huge deal but I think at least $$$\mathcal{O}(tn^2)$$$ solutions could be blocked. There are too many such solutions in C++ but harder to pass with bad constant and slower languages. $$$n \le 10^4$$$, or even larger $$$n$$$ with fewer test cases wouldn't have made anything worse (also why 2-second TL?)
Also, I don't see why keeping the initial $$$t \le 10^5$$$ couldn't be an option. You could simply increase the upper limit of $$$n$$$ to something like $$$10^6$$$ so that you can put enough large cases in test 2 without duplicates. It's not like you need to put every possible case to test correctness.
To be honest, I think just $$$t \le 1000$$$ and $$$n \le 10^9$$$ can't be any weak or something and it prevents $$$\mathcal{O}(tn)$$$ perfectly.
To answer the latter, coordinator wanted me to make $$$n$$$ small enough so every value of $$$n$$$ could be tested.
Well, I find it quite unnecessary but anyways I kinda feel sad to see it's on a vague boundary of allowing some quadratic solutions now.
When I read that problem I was like I have solved this before on codechef
I can't wait for the cry expose blog.