Daniel Fischer wrote: > Needs an Ord constraint: > > inserts :: [a] -> [a] -> [[a]] > inserts [] ys = [ys] > inserts xs [] = [xs] > inserts xs@(x:xt) ys@(y:yt) = [x:zs | zs <- inserts xt ys] > ++ [y:zs | zs <- inserts xs yt]
Heh, I came up with basically the same thing. I'd call this function 'merges' - it returns all possibilities for merging two given lists. > uniquePermutations :: Ord a => [a] -> [[a]] > uniquePermutations = foldr (concatMap . inserts) [[]] . group . sort Which can also be written as uniquePermutations = foldM merges [] . group . sort Bertram _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
