Amneesh Singh
38201248c4
not the cleanest, im still learning parsing in hs Signed-off-by: Amneesh Singh <natto@weirdnatto.in>
35 lines
739 B
Haskell
35 lines
739 B
Haskell
import Data.Char (isDigit)
|
|
import Text.ParserCombinators.ReadP
|
|
( ReadP,
|
|
char,
|
|
many1,
|
|
readP_to_S,
|
|
satisfy,
|
|
)
|
|
|
|
main :: IO ()
|
|
main = do
|
|
input <- map (fst . last . readP_to_S parse) . lines <$> readFile "day4.in"
|
|
putStr "Q1: "
|
|
print $ q1 input
|
|
putStr "Q2: "
|
|
print $ q2 input
|
|
|
|
parse :: ReadP ((Int, Int), (Int, Int))
|
|
parse = do
|
|
a <- readInt
|
|
char '-'
|
|
b <- readInt
|
|
char ','
|
|
c <- readInt
|
|
char '-'
|
|
d <- readInt
|
|
return ((a, b), (c, d))
|
|
where
|
|
readInt :: ReadP Int
|
|
readInt = read <$> many1 (satisfy isDigit)
|
|
|
|
q1, q2 :: [((Int, Int), (Int, Int))] -> Int
|
|
q1 = length . filter (\((a, b), (c, d)) -> a >= c && b <= d || c >= a && d <= b)
|
|
q2 = length . filter (\((a, b), (c, d)) -> b >= c && a <= d)
|