Hot on the heels of Finland's contest, the Swedish olympiad finals also took place this weekend, and for those who want to try out the problems, we have put up a site where you can participate during any 5 hour period during this week: https://pofinal19-open.kattis.com/.
If you don't have 5 hours to spare you can also look at the problems directly at https://pofinal19.kattis.com/. The last problem is IMO quite neat.
Is this full feedback? Are there hidden system tests?
Yep, full feedback.
The last one appears to be the same as this problem.
Oh, you're right. That's further back in ICPC history than I've looked. :) I guess it's not too surprising that it has appeared before given the simple graph reformulation, though it does at least require a bit of thinking to reduce it to that.
Well in that problem you could get away with a O(n^4) solution, here you need to tweak it to be O(n^3)... :/
Mine turned out quite horrible. Time to read the spoilers to see if there's a more beautiful way. ^^
I had an O(n^3 log n) solution for that problem. I find it not obvious how to improve the solution for the sparse case where |E| is smaller than n^2. I agree that it is a tough problem, it took me several hours to get AC at the Live archive.
Going to publish the scoreboard? (been waiting since morning :D)
Thank you for the reminder! Done.
Edit: also, spoilers are available in Swedish at https://github.com/nordicolympiad/swedish-olympiad-2019-public/tree/master/final/spoilers, see the .tex files. Hopefully Google Translate can do a decent job on them.
damn, it's the biggest word I've ever seen :D