To get better at Golang, I decided to try solving Codeforces (CF) problems in Go. I was a bit surprised that the current Go version on CF is (out-of-dated) 1.2, while the current stable Go version is 1.5.
Having said that, my solution for this C div 2 produced correct answers for the given two sample testcases on my computer (with Go 1.5), but gave wrong answers on CF. I've looked at the issue for a while, but could not understand the cause. Could anyone give me some hint?

By the way, is there any plan to update the Go version on Codeforces? I'm not sure who (Mike Mirzayanov?) I should ask for this, though.

Hi everyone, This is my very first Codeforces (CF) blog and my question is:

For people who can solve A,B,C (CF-Div2) level problems comfortably, how can they train to improve their skill to solve problems of D,E (Div2)/B,C (Div1) level efficiently. "Efficiently" here means within the contest time, or reasonably quick, e.g. less than 1h.

I know practice makes perfect, and did read some helpful blogs about practicing with DP problems, or some advanced data structure/algorithms, such as segment tree, suffix array, Z-algorithm, etc. However, I'd like to ask for more concrete and comprehensive advice/suggestions. For instance,

• what specific types of problems, algorithms, or data structures, etc., should we be familiar with?
• Besides algorithmic skill, what specific programming skill do we need to obtain?

Also, if you know helpful resources, such as tutorial, books, websites other than Codeforces, Topcoder, please share them. I think a lot of people, like me would be very grateful for your help. Thanks in advance!