Recently I was trying to solve 266D - BerDonalds from Codeforces Round 163 (Div. 2), and I tried to understand the tutorial posted by the author. But then I realized that the tutorial for this problem was impossible(at least for me) to understand and that the first solution for this problem was wrong or incomplete!! So I think that this is still a problem here on CF!! Tutorials sometimes can be very weak!! Authors should take care of Tutorials as they do with the problems of the rounds!!!

If somebody could help me to understand 266D - BerDonalds I will appreciate it!! Thanks!!!

Maybe the problem is that in most of the tutorials the authors only throw some ideas but not the whole solution. I think that maybe they can make two posts:

1st: Some hints to solve the problem

2nd: The whole solution

I also think that it will be helpful to make setter and tester solutions available.

For example in the turorial for this problem the author says that there is a O(n^3) solution from RAD, but I wonder where can I find this solution.

Congratulations to gen for Codeforces Round 165 (Div. 2), all the problems were interesting but simple, and because the Tutorial was very helpful and well organized!!! I hope that some day all Tutorials could be like this one