Consider the n-Queens problem, in which we are tasked with placing n chess queens on an n x n board in a configuration such that no queen can attack any other queen on the board in a single move. For example, here's a valid configuration for the 4-queens problem:
And here's an invalid configuration:
1. What are the variables, domain, and constraints for this problem when n = 8?
2. Depict this as a constraint graph where the variables are nodes and constraints are represented as edges between the two variable nodes involved.