(List(),List(1, 2, 3, 4, 5, 6, 7, 8))
(List(1, 2, 3, 4),List(5, 6, 7, 8))
(List(1, 2, 3, 4, 5, 6, 7, 8),List())

(List(),List(8, 7, 6, 5, 4, 3, 2, 1))
(List(4, 3, 2, 1),List(8, 7, 6, 5))
(List(8, 7, 6, 5, 4, 3, 2, 1),List())

(List(),List(7, 2, 1, 5, 4, 3, 8, 6))
(List(2, 1, 4, 3),List(7, 5, 8, 6))
(List(7, 2, 1, 5, 4, 3, 8, 6),List())

List(1, 2, 3, 4, 5, 6, 7, 8)

(List(),List(1, 2, 3, 4, 5, 6, 7, 8))
(List(1, 2, 3, 4),List(5, 6, 7, 8))
(List(1, 2, 3, 4, 5, 6, 7, 8),List())

(List(),List(8, 7, 6, 5, 4, 3, 2, 1))
(List(4, 3, 2, 1),List(8, 7, 6, 5))
(List(8, 7, 6, 5, 4, 3, 2, 1),List())

(List(),List(7, 2, 1, 5, 4, 3, 8, 6))
(List(2, 1, 4, 3),List(7, 5, 8, 6))
(List(7, 2, 1, 5, 4, 3, 8, 6),List())

List(1, 2, 3, 4, 5, 6, 7, 8)

List(List())
List(List(), List(1))
List(List(), List(2), List(1), List(1, 2))
List(List(), List(3), List(2), List(2, 3), List(1), List(1, 3), List(1, 2), List(1, 2, 3))
List(List(), List(4), List(3), List(3, 4), List(2), List(2, 4), List(2, 3), List(2, 3, 4), List(1), List(1, 4), List(1, 3), List(1, 3, 4), List(1, 2), List(1, 2, 4), List(1, 2, 3), List(1, 2, 3, 4))

queens(1) = List(List((1,1)))
queens(2) = List()
queens(3) = List()
queens(4) = List(List((4,3), (3,1), (2,4), (1,2)), List((4,2), (3,4), (2,1), (1,3)))

queens(1) = List(List(1))
queens(2) = List()
queens(3) = List()
queens(4) = List(List(3, 1, 4, 2), List(2, 4, 1, 3))