Add Day 5, Puzzle 1 solution

README.md

@@ -6,5 +6,5 @@
 |02 |★ ★  |08 |     |
 |03 |★ ★  |09 |     |
 |04 |★ ★  |10 |     |
-|05 |     |11 |     |
+|05 |★    |11 |     |
 |06 |     |12 |     |

adventofcode2025.cabal

@@ -34,3 +34,4 @@ executable adventofcode2025
     Day02
     Day03
     Day04
+    Day05

src/Day05.hs

@@ -0,0 +1,34 @@
+{-# OPTIONS_GHC -Wno-x-partial #-}
+
+module Day05
+  ( day05_1,
+  )
+where
+
+import Data.List.Split (splitOn)
+
+getRange :: String -> (Int, Int)
+getRange [] = (0, 0)
+getRange r =
+  let x = read . head $ splitOn "-" r
+      y = read . last $ splitOn "-" r
+   in (x, y)
+
+isFresh :: Int -> [(Int, Int)] -> Bool
+isFresh _ [] = False
+isFresh ingredient (r : rs)
+  | ingredient >= fst r && ingredient <= snd r = True
+  | otherwise = isFresh ingredient rs
+
+parseInput :: IO [String]
+parseInput = do
+  lines <$> readFile "input/day5.txt"
+
+day05_1 :: IO ()
+day05_1 = do
+  input <- parseInput
+  let ranges = map getRange $ takeWhile (/= "") input
+      freshIngredients = filter (`isFresh` ranges) . map read . drop 1 $ dropWhile (/= "") input :: [Int]
+  putStrLn $
+    "Day 5, Puzzle 1 solution: "
+      ++ show (length freshIngredients)

src/Main.hs

@@ -4,6 +4,7 @@ import Day01 (day01_1, day01_2)
 import Day02 (day02_1, day02_2)
 import Day03 (day03_1, day03_2)
 import Day04 (day04_1, day04_2)
+import Day05 (day05_1)
 import System.Environment (getArgs)
 
 main :: IO ()
@@ -30,6 +31,9 @@ main = do
     "4" : _ -> do
       day04_1
       day04_2
+    "5" : "1" : _ -> day05_1
+    "5" : _ -> do
+      day05_1
     "all" : _ -> do
       day01_1
       day01_2
@@ -39,4 +43,5 @@ main = do
       day03_2
       day04_1
       day04_2
+      day05_1
     _ -> error "Not implemented"