Edit: The problemset will be used in OpenCup round and so, if you are taking part, please do not discuss the problems(or view the standings) until Nov 22, 2015.

CERC 2015 is over. University of Warsaw, University of Wroclaw and Jagiellonian university qualified. Comenius University, University of Zagreb and Charles University of Prague are also likely to qualify. Congratulations to all these teams.

I am neither European nor do I have any affiliation towards the contest but I needed to congratulate Swistakk, Marcin_smu and mnbvmar for their clean sweep :D

Good luck at the ICPC finals!

Hi, is it possible to follow a blog here in codeforces? That is, I want to be notified by e-mail of any new comments in the blog in future. It helps when someone asks a nice question and I am not able to solve it after trying for some time and I would like to be notified of any future comments.

Hi, it seems that many query-update problems in trees which I normally solve using HLD can be solved by a certain divide and conquer approach(I believe) called centroid decomposition. For example, see here.

It seems like a really cool technique but I am unable to find more about it in google search. Someone please give me links to learn it or write a description on what it is and how it can be used.

Thank you :)