Time for an 2014 update…

Task/N-queens-problem/Haskell/n-queens-problem-3.hs

@@ -0,0 +1,12 @@
+import Data.List (nub, permutations)
+
+-- checks if queens are on the same diagonal
+-- with [0..] we place each queen on her own row
+check f = length . nub . zipWith f [0..]
+
+-- filters out results where 2 or more queens are on the same diagonal
+-- with [0..n-1] we place each queeen on her own column
+generate n = filter (\x -> check (+) x == n && check (-) x == n) $ permutations [0..n-1]
+
+-- 8 is for "8 queens"
+main = print $ generate 8