How did CSES problem-set help you improve in CP?
Who should use it?
Can it be used to prepare for ICPC, CodeJam, Hackercup?
Currently I am an expert(1800+) and want to become Master+. I also want to perform well in contests like CodeJam, HackerCup, etc. Should I solve CSES problems, or only Codeforces problems are enough?