day 4

2022/day04.hs

@@ -0,0 +1,24 @@
+import Data.List.Split (splitOn)
+
+type Quad = ((Int, Int), (Int, Int))
+
+parseQuad :: String -> Quad
+parseQuad s = (parsePair a, parsePair b) where
+    [a,b] = splitOn "," s
+    parsePair s = let [x,y] = splitOn "-" s in (read x, read y)
+
+part1 :: Quad -> Bool
+part1 ((a,b), (x,y)) = (a <= x && b >= y) || (x <= a && y >= b)
+
+part2 :: Quad -> Bool
+part2 ((a,b), (x,y)) = (a <= x && b >= x) || (x <= a && y >= a)
+
+main :: IO ()
+main = do
+    x <- map parseQuad . lines <$> getContents
+    
+    putStr "part 1: "
+    print $ length (filter part1 x)
+    
+    putStr "part 2: "
+    print $ length (filter part2 x)

2022/inputs/day04.test

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+2-4,6-8
+2-3,4-5
+5-7,7-9
+2-8,3-7
+6-6,4-6
+2-6,4-8