From: Neil Smith <neil.git@njae.me.uk>
Date: Tue, 6 Dec 2016 10:14:18 +0000 (+0000)
Subject: Removed the Data.Map
X-Git-Url: https://git.njae.me.uk/?a=commitdiff_plain;h=3b8c2b217a88f32329e5453296887b3c11f81841;p=advent-of-code-16.git

Removed the Data.Map
---

diff --git a/advent06.hs b/advent06.hs
index 0d32e4c..e2a41e7 100644
--- a/advent06.hs
+++ b/advent06.hs
@@ -1,11 +1,7 @@
--- Better version of advent06.hs, using more standard library functions.
-
 module Main(main) where
 
-import Data.List (transpose, maximum, minimum)
-import Data.Char (isLetter)
+import Data.List (transpose, maximum, minimum, sort, group)
 import Data.Tuple (swap)
-import qualified Data.Map.Lazy as Map
 
 main :: IO ()
 main = do 
@@ -16,17 +12,11 @@ main = do
 
 part1 :: [String] -> IO ()
 part1 message = do 
-    putStrLn $ map (fst) $ map (mostCommon) $ map (countedLetters) $ transpose message
+    putStrLn $ map (snd . maximum . counts) $ transpose message
 
 part2 :: [String] -> IO ()
 part2 message = do 
-    putStrLn $ map (fst) $ map (leastCommon) $ map (countedLetters) $ transpose message
-
-countedLetters :: String -> [(Char, Int)]
-countedLetters name = Map.toList $ Map.fromListWith (+) [(c, 1) | c <- filter (isLetter) name]
-
-mostCommon :: [(Char, Int)] -> (Char, Int)
-mostCommon = swap . maximum . map (swap)
+    putStrLn $ map (snd . minimum . counts) $ transpose message
 
-leastCommon :: [(Char, Int)] -> (Char, Int)
-leastCommon = swap . minimum . map (swap)
+counts :: (Eq a, Ord a) => [a] -> [(Int, a)]
+counts = map (\g -> (length g, head g)) . group . sort
\ No newline at end of file