Exercise 3.7 [nqueens-size-exercise]

Consider the $n$-queens problem using the “efficient” incremental formulation given on page nqueens-page. Explain why the state space has at least $\sqrt[3]{n!}$ states and estimate the largest $n$ for which exhaustive exploration is feasible. (Hint: Derive a lower bound on the branching factor by considering the maximum number of squares that a queen can attack in any column.)