I did really poorly in Round 562 Div 2 managing to only solve problem A. I did manage to come up with a logically correct solution for problem B, but it was too inefficient and timed out. After the contest I had to look at solutions of others to understand how to speed up my solution for B. I never even got a chance to look at C,D,E.
How would you go about upsolving? I did already look at problem C, and I think I might be able to come up with something after a while, but what about D, and E? Is it even worth upsolving those if I'm struggling with B level problems? Also how much time should one spend trying to upsolve before looking at solutions?