+28

2 files changed, 25 insertions, 0 deletions

diff --git a/h28.hs b/h28.hs
new file mode 100644
index 0000000..0ff75cc
--- /dev/null
+++ b/h28.hs
@@ -0,0 +1,11 @@
+import Data.List
+import Data.Ord (comparing)
+import Data.Function
+
+lsort :: [[a]] -> [[a]]
+lsort = sortBy (comparing length)
+
+lsort' = sortBy (\xs ys -> compare (length xs) (length ys))
+
+lsort'' = sortBy (compare `on` length)
+
diff --git a/h28n.hs b/h28n.hs
new file mode 100644
index 0000000..bf584c7
--- /dev/null
+++ b/h28n.hs
@@ -0,0 +1,14 @@
+import Control.Arrow ((>>>), (&&&), second)
+import GHC.Exts (sortWith)
+
+lfsort :: [[a]] -> [[a]]
+lfsort = zip [1..] >>> map (second (length &&& id)) >>> sortWith (snd>>>fst)
+            >>> cntDupLength undefined [] >>> sortWith (snd>>>fst) 
+            >>> sortWith fst >>> map (\(_,(_,(_,a))) -> a)
+    where 
+        cntDupLength :: Int -> [(Int,(Int,a))] -> [(Int,(Int,a))] -> [(Int,(Int,(Int,a)))]
+        cntDupLength _ lls [] = map ((,) (length lls)) $ reverse lls
+        cntDupLength _ [] (x@(_,(l,_)):xs) = cntDupLength l [x] xs
+        cntDupLength l lls ys@(x@(_,(l1,_)):xs)
+            | l == l1   = cntDupLength l (x:lls) xs
+            | otherwise = (map ((,) (length lls)) $ reverse lls) ++ cntDupLength undefined [] ys