![]() I don't have a formal proof, but this is what I thought of :īase : If array has 1 or we managed to generate 1 then it is possible to generate each and every element from 1.max(array).ġ) gcd is 1 for the whole array, so it means that there lies 2 elements which does not have common divisor, so let's assume it as 4 and 599, now you can generate values as 599 - 4, 599 - (4 * 2). Overall the contest was very well prepared, the problems were nice, and the difficulties were on the spot. After reading the solution, I don't think anymore it is a great problem, still a very nice one though (because it seems totally impossible without the right idea). I cannot solve it even with $$$n$$$ queries. G: Thought about this one for 30 minutes straight.Then, I passed the pretests with a randomized solution which I am not 100% should pass the tests (since it may be too slow). The observation that we can understand if $$$i,j$$$ are adjacent by looking at $$$f(i,\cdot)-f(j,\cdot)$$$ is cool (I was lucky and it was the first thing I tried). One is naturally lead to try and "get the biggest possible number" but the correct strategy is to go backward and I needed quite some time to understand it. But the first two were wrong (not a bug, the algorithm was wrong). I sent 3 solutions, and I thought I had a proof for all of them. I am not a fan since I knew what to do immediately after reading the statement (and then I did a mess. D: Standard problem, appropriate difficulty.I did not prove my solution, though I think that I can prove it in 5 minutes. B: Somewhat standard, but ok (set of integers, operations, what can you get? -> gcd). ![]() First time in my life I submit without checking the correctness on the examples. ![]() Here is some feedback on the problem set: □□□Īs always, hope you all gain non-negative ratings $$$\Delta$$$ in this round! □□□ There is an interactive problem, so please see the guide of interactive problems if you are not familiar with it.Number of problems: 8 problems, one split into 3 subtasks □□□.Duration: 2 hours and 30 minutes □□□.MikeMirzayanov for amazing platform Codeforces and Polygon.Our testers for testing and providing invaluable feedbacks: Rebelz, Heltion, ShmilyTY, dXqwq, Aestas16, SSerxhs, Qiuly.qwq, Leasier, Yakumo_Ran, Nanako, Celtic, JohnVictor, installb, mafailure, CuiZhenhang, lunchbox, _rey, Wolam, LLL_2820, mejiamejia, TomiokapEace, QAQ_QWQ, mkisic, Mahfel, luanmenglei, ak2006 and NishikigiChisato.Wolam for proposing rejected problems.The problems were written and prepared by Cocoly1990, waaitg and Imakf. Thanks to XTX, which in 2022 supported the global rounds initiative! The best 20 participants over all series get sweatshirts and place certificates.The final result for each participant is equal to the sum of points he gets in the four rounds he placed the highest.In each round top-100 participants get points according to the table.The prizes for the 6-round series in 2022: 20 t-shirts are randomly distributed among those with ranks between 31 and 500, inclusive.The rounds are open and rated for everybody. It is the sixth round of a 2022 series of Codeforces Global Rounds. ![]() On Nov/26/2022 17:05 (Moscow time) we will host Codeforces Global Round 24. ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |