I have noticed that, in terms of rating, the country with the highest average on Codeforces is China. However, when I check their profiles, I often find that most of them, from CM to LGM, participate almost exclusively in contests on Codeforces.
Of course, success doesn't come overnight, but I want to know—what was your playground when you just started?
Or which platform did you find most educational for learning competitive programming effectively ?
Any resourse that will help ?
China has its own algorithm competition called the Olympiad in Informatics, abbreviated as OI, in which students participate. This is why most Chinese people on CF are students.
There are also some OJ in China, such as luogu,Universal Online Judge and QOJ.And there are also some training platforms on campus.
No matter what you are learning CP for, if you want to improve, I think Codeforces/Atcoder is a must. Grinding problems on them helps you to understand algorithms better and improve your reasoning skills. However, I feel that these two platforms have somewhat high entrance. I had studied CP for a year and then struggled even with the easiest problems on Codeforces.
If you want to specialize your skill in OI competitions, Luogu is a good addition. These problems generally contain more advanced algorithm and more implementation, which is what you need for OI style contests, compared to problems of same level in Codeforces. For example, you would expect things like FFT or number theory tricks at 2000-2500 level (which corresponds to "purple" problems in Luogu). It is also a good point to start with, as there are easy problems in Luogu that helps you get familiar with C++ language.
I LIKE UOJ the best,it's question quality is much higher than luogu