Recently, I noted a funny thing about various views on codeforces’ problem.

In China, majority of competitive programmers described codeforces like “a good website for practicing your thinking” and “ advanced algorithms and data structure not necessarily required” (especially common in participants of Informatics Olympic).

At the same time, I saw some on codeforces said that codeforces’ problem have too much certain algorithms and data structure.

One possible reason for this may be that we(Chinese) consider the data structure vital and train mostly by some data structure problems .

So,what’s your point on codeforces’ problem? Further more, what do you think about the problems based on thinking and observation? What do you think about the problems based on a certain advanced algorithm or data structure?