Hi, everyone and I hope you are doing well!

Recently, I started to solve some graph problems like this:

https://mirror.codeforces.com/problemset/problem/1045/C https://mirror.codeforces.com/contest/231/problem/E

I'm trying to figure out if I need to learn something to handle this kind of problems, so I will glad if you can share with me problems like that and some tricks, thank you!