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@IronGremlin
Last active September 12, 2020 16:53
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Attempt at recursion-schemes
import qualified Data.Set as S
import qualified Data.Map.Strict as M
import Data.List.Split (splitOn)
import Data.List (stripPrefix)
import Data.Maybe (fromJust)
newtype Fix f = In { out :: f (Fix f) }
type Algebra f a = f a -> a
cata :: (Functor f) => Algebra f a -> Fix f -> a
cata f = f . fmap (cata f) . out
type Coalgebra f a = a -> f a
ana :: (Functor f) => Coalgebra f a -> a -> Fix f
ana f = In . fmap (ana f) . f
hylo :: Functor f => Algebra f a -> Coalgebra f b -> b -> a
hylo f g = h where h = f . fmap h . g
data PipeGraph a =
PipeGraph Int [a]
deriving (Eq,Show,Functor)
data Pipes =
Pipes Int [Pipes]
deriving (Eq,Show)
type GoodGraph = Fix PipeGraph
input = readFile "./test/Golden/DigPlum.txt"
sample = "0 <-> 2\n1 <-> 1\n2 <-> 0, 3, 4\n3 <-> 2, 4\n4 <-> 2, 3, 6\n5 <-> 6\n6 <-> 4, 5"
bmap f f' (x,y) = (f x, f' y)
handleLine :: String -> (Int, [Int])
handleLine = bmap read (map read. splitOn ", ") . fmap (fromJust . stripPrefix " <-> ") . span (/=' ')
toMap :: String -> Map Int [Int]
toMap = M.fromList . map handleLine . lines
getPair :: Ord k => Map k v -> k -> (k,v)
getPair m key = (key, m ! key)
buildGraph :: Map Int [Int] -> Coalgebra PipeGraph Int
buildGraph master k = let (z,zs) = getPair master k in PipeGraph z zs
deconGraph :: Algebra PipeGraph Pipes
deconGraph (PipeGraph z zs) = Pipes z zs
toPipes :: Map Int [Int] -> Int -> Pipes
toPipes m = hylo deconGraph (buildGraph m )
getUniq :: Pipes -> Set Int
getUniq (Pipes n ps) = go (S.singleton n) ps
where go xs [] = xs
go xs ((Pipes a as):zs) = if a `S.member` xs
then go xs zs
else go (S.insert a xs) (zs ++ as)
numberOfMembersFromZero :: IO ()
numberOfMembersFromZero = do
baseM <- toMap <$> input
let resSet = getUniq . toPipes baseM $ 0
print resSet
putStrLn "Length Was: "
print (S.size resSet)
uniqueGroups :: IO ()
uniqueGroups = do
baseM <- toMap <$> input
let resGroups = M.elems $ M.mapKeys (getUniq . toPipes baseM) baseM
putStrLn "Number of unique groups:"
print $ S.size (S.fromList resGroups)
@IronGremlin
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Attempted solution to AoC_2017_Day12 using recursion schemes.

Still not sure how to refactor 'getUniq' -
I don't think use of the Pipes data type should be necessary here, it seems like a solution should be available in paradigm, but resources on the topic are pretty limited. Research continues.

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