1 files changed, 14 insertions, 0 deletions
diff --git a/2017/4.hs b/2017/4.hs
new file mode 100644
index 0000000..2f541c6
--- /dev/null
+++ b/2017/4.hs
@@ -0,0 +1,14 @@
+import Control.Monad
+import Data.List
+
+hasDups :: Eq a => [a] -> Bool
+hasDups (a:b:cs) | a == b = True
+                 | otherwise = hasDups (b:cs)
+hasDups _ = False
+
+main :: IO ()
+main = do
+    input <- liftM (map words . lines) (readFile "4.in")
+
+    print $ sum $ map (fromEnum . not . hasDups . sort) input
+    print $ sum $ map (fromEnum . not . hasDups . sort . map sort) input