[99p]NQueens

import Data.List
-- N Queens (n: # of Queens, m: length of boarder; for instance, run eight queens as nQueen 8)
queeN :: Int -> Int -> [[Int]]
queeN 0 _ = [[]]
queeN n m = [ q:qs | qs <- queeN (n-1) m, q <- [1..m] \\ qs,  noDiag q qs ]
          where noDiag q qs = foldr (&&) True [ abs(q - qs!!(i-1)) /= i | i<-[1..(n-1)] ]
nQueen n = queeN n n