64 lines
1.6 KiB
Agda
64 lines
1.6 KiB
Agda
module Day19
|
||
|
||
import Prelude
|
||
import Node
|
||
import Aoc
|
||
|
||
Rules : U
|
||
Rules = List (List Char)
|
||
|
||
data Problem : U where
|
||
MkP : Rules → Rules → Problem
|
||
|
||
parseFile : String -> Either String Problem
|
||
parseFile text =
|
||
let (a :: b :: Nil) = split (trim text) "\n\n" | xs => Left $ (show $ length xs) ++ " parts"
|
||
in Right (MkP (map unpack $ split a ", ") (map unpack $ lines b))
|
||
|
||
State : U
|
||
State = List (Int × List Char)
|
||
|
||
matches : Rules -> List Char -> Int
|
||
matches rules text = go (map (_,_ 1) rules) text
|
||
where
|
||
step : State -> Char -> State -> State
|
||
step acc c Nil = acc
|
||
step acc c ((n, Nil) :: rs) = step acc c rs
|
||
step acc c ((n, (x :: xs)) :: rs) = if x == c
|
||
then step ((n, xs) :: acc) c rs
|
||
else step acc c rs
|
||
|
||
nils : Int -> State -> Int
|
||
nils acc Nil = acc
|
||
nils acc ((n, Nil) :: xs) = nils (acc + n) xs
|
||
nils acc (x :: xs) = nils acc xs
|
||
|
||
go : State -> List Char -> Int
|
||
go st Nil = nils 0 st
|
||
go st (c :: cs) = case nils 0 st of
|
||
0 => go (step Nil c st) cs
|
||
n => let st = map (_,_ n) rules ++ st
|
||
in go (step Nil c st) cs
|
||
|
||
part1 : Problem -> IO Unit
|
||
part1 (MkP rules msgs) = do
|
||
let (r :: rs) = rules | _ => putStrLn "no rules"
|
||
let out = map (matches rules) msgs
|
||
let p1 = length $ filter (_/=_ 0) out
|
||
putStrLn $ "part1 " ++ show p1
|
||
let p2 = foldl _+_ 0 out
|
||
putStrLn $ "part2 " ++ show p2
|
||
|
||
run : String -> IO Unit
|
||
run fn = do
|
||
putStrLn fn
|
||
text <- readFile fn
|
||
let (Right prob) = parseFile text | Left err => putStrLn err
|
||
part1 prob
|
||
|
||
|
||
main : IO Unit
|
||
main = do
|
||
run "aoc2024/day19/eg.txt"
|
||
run "aoc2024/day19/input.txt"
|