Does Timus have a problem classifier except Timus problem Classifier. I wish it was a bit more specific.

I tried to solve the problem today, but I can't find any ideas? Can someone help me? Is there an issue similar to this one? https://vietnam-national20.kattis.com/problems/infinite2darray

• I am not a beginner to CP, I had some time practicing on another judge (also in camps), now I can solve some problems 1800-1900, sometimes higher (2000), but in my recent virtual join, i didn't solve the problem with 1300 rank, am i really depressed for the next problem (DEF)? What should I do? Am I too weak in some parts? Or is my implementation poor?
• Can you give me some advice? Such as how to practice. Before asking this question I have consulted through similar articles on CF or quore but only get some general answers such as "practice a lot", "code on paper", "practice by topic" , "try to do articles with 100-200 rating higher than your current rating".
• Is there a way to find the good of my weaknesses? Are good observations improved? For example I am weak "greedy", should I do all "greedy" on a2oj or something like that?