import CW9a._

assert(legal_moves(8, Nil, (2,2)) == 
             List((3,4), (4,3), (4,1), (3,0), (1,0), (0,1), (0,3), (1,4)))
assert(legal_moves(8, Nil, (7,7)) == List((6,5), (5,6)))
assert(legal_moves(8, List((4,1), (1,0)), (2,2)) == 
       List((3,4), (4,3), (3,0), (0,1), (0,3), (1,4)))
assert(legal_moves(8, Nil, (0,1)) == List((1,3), (2,2), (2,0)))
assert(legal_moves(8, List((6,6)), (7,7)) == List((6,5), (5,6)))
assert(legal_moves(1, Nil, (0,0)) == Nil)
assert(legal_moves(2, Nil, (0,0)) == Nil)
assert(legal_moves(3, Nil, (0,0)) == List((1,2), (2,1)))