module Day6.Main (main) where

import System.IO
import Data.List

main :: IO ()
main = do
    putStrLn "Day 6"
    
    handle <- openFile "app/Day6/input" ReadMode
    contents <- hGetContents handle

    let r1 = part1 contents
    putStrLn $ "part 1: " ++ show r1

    let r2 = part2 contents
    putStrLn $ "part 2: " ++ show r2

distinct xs = length (nub xs) == length xs

part1 :: String -> Int
part1 contents = go contents 0
    where
        go []           _ = 0
        go (a:b:c:d:es) n | distinct [a,b,c,d] = n + 4
        go (a:es)       n = go es (n + 1)

part2 :: String -> Int
part2 contents = go contents 0
    where
        go []           _ = 0
        go (e:es) n = if distinct (e : take 13 es)
                      then n + 14
                      else go es (n + 1)