Hello codeforces !

my question is How contests get distributed over days ?

why sometimes we have 9 days without div 2 or div 1 contests in a row ( for example, [19, 26] feb 2025 or [9, 18] dec 2024 ), but sometimes we have three consecutive contests in three days ? ( for example, 26,27 and 28 October 2024 )

I found an interesting problem in the archive of Iran National OI problems. The problem statement in English is:

Let D be a weighted directed graph. The length of a path P is defined as the minimum weight of the edges along P. The distance between vertices u and v is the maximum length among all paths from u to v. Your task is to find the distance between every pair of vertices in O(n·e + n²) time.

I have a O(n(e + n) lg n) solution for this using Dijkstra, but I haven't been able to solve it in O(n·e + n²), so I'm looking for a solution. Any help would be appreciated!

Link to the original problem

Hey Codeforces ! there is a tiny bug in verdicts that I saw now, If you submit a solution and wait till it shows the result ( not refreshing the page ), It will show "Accepted" instead of "Happy New Year!"

Who determines the contest start time ? The writer(s) or Mike Mirzayanov?

if you take a look at upcoming contests, You will notice that 3 unusual start times are there.

this unusual start time happened in some of recent contests too. I am familiar with 14:35 UTC start time ( I think 54 out of 56 contests I participated, started at that time, and that 2 contests started at 10:35 UTC I think, which both were on Friday ).