From 0e134abdaa4947895354ac7afbb99157aef178fd Mon Sep 17 00:00:00 2001
From: Gattix <gattix@cock.li>
Date: Sat, 9 Dec 2023 18:41:37 +0100
Subject: [PATCH] more day09 golfing

p2 is just reverse p1 lol
---
 2023/day09/day09.hs | 11 ++++-------
 1 file changed, 4 insertions(+), 7 deletions(-)

diff --git a/2023/day09/day09.hs b/2023/day09/day09.hs
index 245eb4b..ea8ff26 100644
--- a/2023/day09/day09.hs
+++ b/2023/day09/day09.hs
@@ -3,15 +3,12 @@ import Control.Arrow
 main :: IO ()
 main = do
   input <- parse <$> readFile "input"
-  print $ day09 input
+  print $ (day09 &&& day09 . map reverse) input
 
 parse :: String -> [[Int]]
 parse = map (map read . words) . lines
 
-day09 :: [[Int]] -> (Int, Int)
+day09 :: [[Int]] -> Int
 day09 =
-  (sum *** sum) .
-  unzip .
-  map
-    ((sum . map last &&& foldr1 (-) . map head) .
-     takeWhile (not . null) . iterate (zipWith (-) =<< tail))
+  sum .
+  map (sum . map last . takeWhile (not . null) . iterate (zipWith (-) =<< tail))