AoC/2019/day7/day7.hs

import Data.List.Split
import qualified Data.List as L
import Data.Vector as V
import Data.Char
import System.Exit

main = do
    content <- readFile "input"
    let tape = fromList $ L.concatMap (L.map read . splitOn ",") (lines content)
    print $ find_max tape [0..4]
    print $ find_max tape [5..9]

run_amps_feedback tape intseq = L.head $ run_amps_feedback' tms intseq [0]
    where tms = L.replicate 5 (tape,0)
run_amps_feedback' ((t,p):tms) intseq prev =
    if halt == Halt then prev else
        run_amps_feedback' (tms L.++ [tm_new]) tailseq tm_out
    where (tm_new,tm_in,tm_out,halt) = exec_steps ((t,p),xprev,[],Continue)
          tailseq = if L.null intseq then [] else L.tail intseq
          xprev = if L.null intseq then prev else (L.head intseq):prev

find_max tape range = L.maximum [run_amps_feedback tape xs | xs <- L.permutations range]

opl x
    | n`L.elem`"1278"=4
    | n`L.elem`"56"=3
    | n`L.elem`"34"=2
    | otherwise=1
    where n = L.last $ show x

parsemodes :: String -> [Bool]
parsemodes m = L.replicate (3 - L.length l) False L.++ l
    where l = L.map (toEnum . digitToInt) m

paramch m opvec t = imap f (V.tail opvec)
    where f i a = if (L.reverse m) !! i then a else t ! a

getopmodes opvec = (op_dedup,parsed_modes)
    where (op,modes) = L.splitAt 2 $ L.reverse $ show $ opvec ! 0
          parsed_modes = parsemodes $ L.reverse modes
          op_dedup = if L.last op == '0' then [L.head op] else op

data OutAction = Continue | Output | Halt deriving (Enum, Eq, Show)

step :: Vector Int -> (Vector Int, Int, [Int], [Int]) -> (Vector Int, Int, OutAction, [Int], [Int])
step opvec (t,p,input,val)
        | op=="1" = ((t // [((V.last opvec), (params ! 0) + (params ! 1))]),p,Continue,input,val)
        | op=="2" = ((t // [((V.last opvec), (params ! 0) * (params ! 1))]),p,Continue,input,val)
        | op=="3" = ((t // [((V.last opvec), L.head input)]),p,Continue,L.tail input,val)
        | op=="4" = (t,p,Output,input,(V.last $ params):val)
        | op=="5" = (t, if (params ! 0)/=0 then (params ! 1) else p,Continue,input,val)
        | op=="6" = (t, if (params ! 0)==0 then (params ! 1) else p,Continue,input,val)
        | op=="7" = ((t // [((V.last opvec), if (params ! 0)<(params ! 1)
                        then 1 else 0)]),p,Continue,input,val)
        | op=="8" = ((t // [((V.last opvec), if (params ! 0)==(params ! 1)
                        then 1 else 0)]),p,Continue,input,val)
        | op=="99" = (t,p,Halt,input,val)
        where (op,m) = getopmodes opvec
              params = paramch m opvec t

exec_steps :: ((Vector Int, Int), [Int], [Int], OutAction) -> ((Vector Int, Int), [Int], [Int], OutAction)
exec_steps ((t,p),input,val,halt) =
    let command_length = opl $ t ! p
        opvec = slice p command_length t
        (t_new,p_new,cond,input_new,val_new) =
            step opvec (t,p+command_length,input,val) in
    if cond == Output || cond == Halt then ((t_new,p_new),input_new,val_new,cond)
        else exec_steps ((t_new,p_new),input_new,val_new,cond)