Nim games are very famous in Competitive programming. Generally, I try to guess any random idea, sometimes it works and most of the time it doesn't :(
So, I am wondering if there is any general approach for these problems because I am getting terrified of games.
My approach is to think about loosing states. And try to find is there any way to force the loosing position on someone.....
Doesn't work everytime, but works well in a lot of problems.