Currently i encountered a Div2-500 Problem at SRM 331 here
When I checked the editorial and the solutions , I found nearly all the solutions the users submitted or the author talked in the editorial was by using bitmask
Why it was so obvious for many users that it can be solved using Bitmasks ?
What are the keywords of a problem that tells us that it can be solved by Bitmasks ? What are the best bitmask problems for someone to start with ?