Advent of Code 2021
You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.

47 lines
1.4 KiB

module Day13_1 where
import System.IO (openFile)
import Data.Text (unpack, splitOn, pack)
import Prelude hiding (splitAt)
import Data.List (nub)
splitAt :: String -> String -> [String]
splitAt delimiter str = map unpack $ splitOn (pack delimiter) $ pack str
insert :: Int -> Char -> [Char] -> [Char]
insert 0 y xs = xs
insert n y [] = []
insert n y xs
| length xs < n = xs
| otherwise = take n xs ++ [y] ++ insert n y (drop n xs)
fold :: String -> (Int, Int) -> (Int, Int)
fold str (x, y)
| head str == 'x' = (fold' x, y)
| head str == 'y' = (x, fold' y)
where coord = read . last $ splitAt "=" str
fold' num
| num > coord = coord - (num - coord)
| otherwise = num
main :: IO ()
main = do
input <- readFile "inputs/13.txt"
let (coords', folds') = (\[a,b] -> (lines a, lines b)) $ splitAt "\n\n" input
--
let coords = (\[a,b] -> (read a, read b) :: (Int, Int)) <$> map (splitAt ",") coords'
folds = map (last . splitAt " ") folds'
let result = map (\(a,b) -> (b,a))
$ nub
$ foldl (\acc x -> map (fold x) acc) coords folds
let width = maximum $ snd <$> result
height = maximum $ fst <$> result
field = (,) <$> [0..height] <*> [0..width]
let display x
| x `elem` result = '#'
| otherwise = ' '
in putStrLn $ insert (width+1) '\n' $ map display field