1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
|
module Main (main) where
import System.Environment
import qualified Data.Bifunctor
main :: IO ()
main = getArgs >>= readFile . head >>= print . solveDay4
solveDay4 :: String -> (Int, Int)
solveDay4 x = (solveDay4Part1 x, solveDay4Part2 x)
solveDay4Part1 :: String -> Int
solveDay4Part1 = length . filter containingRanges . map parseRanges . lines
newtype CleaningCells = CleaningCells (Integer,Integer)
parseRanges :: String -> (CleaningCells, CleaningCells)
parseRanges = Data.Bifunctor.bimap parseRange parseRange . splitAtChar ','
splitAtChar :: Char -> String -> (String, String)
splitAtChar c x = splitAtCharacter c ("",x)
splitAtCharacter :: Char -> (String, String) -> (String, String)
splitAtCharacter c (a, b:bs) = if b == c then (a,bs) else splitAtCharacter c (a++[b], bs)
splitAtCharacter c (a,[]) = (a,[])
parseRange :: String -> CleaningCells
parseRange = CleaningCells . Data.Bifunctor.bimap read read . splitAtChar '-'
containingRanges :: (CleaningCells, CleaningCells) -> Bool
containingRanges (CleaningCells (a1,b1), CleaningCells (a2,b2)) = (a1 >= a2 && b1 <= b2) || (a2 >= a1 && b2 <= b1)
solveDay4Part2 :: String -> Int
solveDay4Part2 = length . filter overlappingRanges . map parseRanges . lines
overlappingRanges :: (CleaningCells, CleaningCells) -> Bool
overlappingRanges (CleaningCells (a1,b1), CleaningCells (a2,b2)) =
(a1 >= a2 && a1 <= b2) || (b1 >= a2 && b1 <= b2) || (a2 >= a1 && a2 <= b1) || (b2 >= a1 && b2 <= b1)
|
