albert wrote on Wed, Sep 23, 2009 10:20 AM UTC:Excellent ★★★★★
One must understand what happens when:
- rook and king are adjacent = the Rook stays where it was.
- rook and king are adjacent with rook in the corner = permute them.
note that rook and king adjacent with king in the corner is not a valid
array, since a valid array implies King between rooks