Welcome to Codeforces Beta Round #87!
The mysterious author of today's match (which turns out to be me) have prepared seven problems for you (five in each division). Since I can't spoil you any of the problems yet, for now I can safely say that I like all of today's problems. The problem statements are wonderfully crafted (and translated) with the help of both RAD and Delinur and they are now very easy to read. My hope is that you will like them as well :).
There will be .png images in some problems, so make sure your browser can support them. You may want to check if you can see the image in the Time to Raid Cowavans problem (authored by Alex_KPR).
And also a warm thanks to it4.kp for testing the problems (for the
fourth fifth time I might add - he tested 4 of my SRMs already :) ) together with RAD, and to MikeMirzayanov and the entire Codeforces team for the great system and this opportunity! Indeed it is through this website that I receive my current internship offer :).
So from Kraków I wish everyone and the Codeforces' server good luck and stay strong :).
The match has ended! Thank you for participating - I enjoyed it :). Here's the Editorial for this match.
The top three of the Division1 solves all five problems! They are followed by al13n and kcm1700 who solved 4 problems in approximately one hour. Congratulations!
In division 2, we have exactly 5 persons who solved all 5 problems, the fastest solved all five problems within 1 hour 4 minutes! Congratulations!
I hope I can author other set next time here. Till we meet again.
If I could turn back time, I would change the following:
1) Swap problem D1-D and D1-E
2) modulo 1,000,003 becomes modulo 1,000,000,007
3) N^2 solutions means N >= 4,000
4) Time limit should be made for Java, not Python...
Lesson learned. And the N^3 solutions which pass turn out to be beautiful after I see them (all of them implements different algorithm after I read them more carefully). Not to mention there's 3 passing N^2 solutions. Okay, I'm content now :) - apologies for my rants yesterday.
=== stale rants below ===
Oh, after the coding phase, you may want to visit this post again.
Guess what? It's starting! Rawr! I'm honored that it broke the maximum number of participants so far - thank you guys :).
Link to standings:
Now that the match is over...
I owe division 2 apologies for making D2-D too easy. Sorry - I didn't see that coming.
Anyway, while you're busy waiting for scores to pop up in your respective division summary, here you go! Editorial for this match.
Okay, so a big apology from me for letting a N^3 solutions to pass D1-D. It didn't cross my mind that N^3 = 2000^3 would run under 2 seconds. I'll make sure not to make things like this happen again in my matches :( - 5000 here I come.