N Knights Problem

graph
independent

#1

Can some body explain How to solve this problem in details…And give link to some similar kind of problem for practice. I have gone through the editorial understood what to do ,But not getting how we can build graph for nodes with two indices row and column and also the maximum independent set part.Thanks in Advance …


#2

Which problem is this?

And most chess problems are solved using state compression (using bitmasks) + DFS search (with possible DP) btw.