Hi Codeforces!. I want to start doing tree problems and I would like some recommendations, videos, material, especially problems with which to start. I thank you in advance for any help.

I see very difficult topic :"3 please help!

Hi! Because what problems start with BFS? Since I saw some problems but they seem too complex to start, could someone recommend some problems with which to start being able to use this algorithm. I thank you in advance.

Hi!, I hope you have a good day. I really want to learn Hashing. I've read some blogs but I can't find one for beginners or a very friendly list of problems to start with. If someone could help me.. thanks in advance.