From ff171b3e022a612d4ed348b5f5dad6bd9fe4562a Mon Sep 17 00:00:00 2001
From: Riley Apeldoorn <me@riley.lgbt>
Date: Sat, 4 Dec 2021 13:09:47 +0100
Subject: [PATCH] More day 4 improvements

---
 4/solution.hs | 29 +++++++++--------------------
 1 file changed, 9 insertions(+), 20 deletions(-)

diff --git a/4/solution.hs b/4/solution.hs
index 32c95b7..797519d 100644
--- a/4/solution.hs
+++ b/4/solution.hs
@@ -14,41 +14,30 @@ parse (l : ls) = (n, b)
 parseBoards :: [String] -> [Board]
 parseBoards [] = []
 parseBoards l  = parse a : parseBoards b
-    where (a,b) = splitAt 5 l 
-          parse = map $ map (Unmarked . read) . words
+    where (a,b) = splitAt 5 l
+          parse = map $ map ((,False) . read) . words
 
 type Board = [[Cell]]
 
-rows :: Board -> [[Cell]]
-rows = id
-
-cols :: Board -> [[Cell]]
-cols = transpose
-
 hasWon :: Board -> Bool
-hasWon b = check (rows b) || check (cols b)
+hasWon b = check b || check (transpose b)
     where check = any $ all marked
 
 score :: Int -> Board -> Int
-score n b = n * sum [ x | c <- b, Unmarked x <- c ]
+score n b = n * sum [ x | c <- b, (x, False) <- c ]
 
 call :: Int -> Board -> Board
 call n = map (map mark)
-    where mark (Unmarked x) | x == n = Marked x
-          mark x = x
+    where mark (x,s) = (x, s || x == n)
 
-data Cell = Unmarked Int
-          | Marked Int
+type Cell = (Int, Bool)
 
 marked :: Cell -> Bool
-marked (Marked _) = True
-marked _          = False
+marked = snd
 
 solve :: Input -> (Int, Int)
-solve input = (f input, g input)
-    where wins extr (n,b) = uncurry score $ extr $ bingo n b
-          f = wins head
-          g = wins last
+solve (n, b) = (head r, last r)
+    where r = map (uncurry score) $ bingo n b
 
 bingo :: [Int] -> [Board] -> [(Int, Board)]
 bingo _ []              = []