AoC/2019/day7/day7.hs

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

data OutAction = Continue | Output | Halt deriving (Enum, Eq, Show)
type Tape = Vector Int
type TapeSection = Vector Int
type TuringMachine = (Tape,Int)

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]

find_max :: Tape -> [Int] -> Int
find_max tape range = L.maximum [run_amps_feedback tape xs | xs <- L.permutations range]

run_amps_feedback :: Tape -> [Int] -> Int
run_amps_feedback tape intseq = L.head $ run_amps_feedback' tms intseq [0]
    where tms = L.replicate 5 (tape,0)

run_amps_feedback' :: [TuringMachine] -> [Int] -> [Int] -> [Int]
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

opl :: Int -> Int
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 :: [Bool] -> TapeSection -> Tape -> TapeSection
paramch m opvec t = imap f (V.tail opvec)
    where f i a = if (L.reverse m) !! i then a else t ! a

getopmodes :: TapeSection -> (String, [Bool])
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

step :: TapeSection -> (TuringMachine, [Int], [Int]) -> (TuringMachine, OutAction, [Int], [Int])
step opvec ((t,p),input,val)
        | op=="1" = (tm_binop (+),Continue,input,val)
        | op=="2" = (tm_binop (*),Continue,input,val)
        | op=="3" = (new_tm t (L.head input),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" = (new_tm t (if (params ! 0)<(params ! 1)
                    then 1 else 0),Continue,input,val)
        | op=="8" = (new_tm t (if (params ! 0)==(params ! 1)
                    then 1 else 0),Continue,input,val)
        | op=="99" = ((t,p),Halt,input,val)
        where (op,m) = getopmodes opvec
              params = paramch m opvec t
              tm_binop x = new_tm t ((params ! 0) `x` (params ! 1))
              new_tm t x = ((t // [((V.last opvec), x)]),p)

exec_steps :: (TuringMachine, [Int], [Int], OutAction) -> (TuringMachine, [Int], [Int], OutAction)
exec_steps ((t,p),input,output,halt) =
    let command_length = opl $ t ! p
        opvec = slice p command_length t
        ((t_new,p_new),cond,input_new,output_new) =
            step opvec ((t,p+command_length),input,output) in
    if cond `L.elem` [Output, Halt] then ((t_new,p_new),input_new,output_new,cond)
        else exec_steps ((t_new,p_new),input_new,output_new,cond)