19 lines
775 B
Haskell
19 lines
775 B
Haskell
|
import Data.Char
|
||
|
|
import Data.List.Split
|
||
|
|
import Data.List
|
||
|
|
|
||
|
|
main :: IO ()
|
||
|
|
main = do
|
||
|
|
input_raw <- map (map digitToInt) <$> lines <$> readFile "day09/input"
|
||
|
|
let nines = take (length (head input_raw)) $ repeat 9
|
||
|
|
let nineIt x = map ((9:) . (++[9])) $ (nines : x ++ [nines])
|
||
|
|
print $ day09 (nineIt input_raw) input_raw
|
||
|
|
|
||
|
|
day09 :: [[Int]] -> [[Int]] -> Int
|
||
|
|
day09 input input_raw = foldl (\acc (x,y) ->if y then acc+1+x else acc) 0 $ zip (concat input_raw) bools
|
||
|
|
where vert = tail $ init $ map ((map isSmol) . divvy 3 1) (transpose input)
|
||
|
|
horz = tail $ init $ map ((map isSmol) . divvy 3 1) input
|
||
|
|
isSmol [a,b,c] = if b<a && b<c then True else False
|
||
|
|
isSmol :: [Int] -> Bool
|
||
|
|
bools = zipWith (&&) (concat (transpose vert)) (concat horz)
|