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day 14: random update

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Signed-off-by: Amneesh Singh <natto@weirdnatto.in>
This commit is contained in:
Amneesh Singh
2022-12-15 14:53:35 +05:30
parent b2881bf9a3
commit e7ad25a79d
1 changed files with 26 additions and 28 deletions
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54
day14.hs
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@@ -3,41 +3,40 @@
import Data.Maybe (fromJust)
import Data.Set (Set)
import qualified Data.Set as S (fromList, insert, lookupMax, member, notMember, union)
import qualified Data.Set as S (fromList, insert, map, member, notMember, union)
import Data.Text (Text)
import qualified Data.Text as T (lines, splitOn, words)
import qualified Data.Text.Read as T (decimal)
import Lib (readFile')
-- ok this is it, this takes 4.54s, kms
-- this can probably be improved using hashtables in ST monad but will try that later
-- times can be improved greatly using Data.HashSet in unordered-containers, but i wont use it
main :: IO ()
main = do
input <- parse . T.lines <$> readFile' "day14.in"
let mx = fst . fromJust $ S.lookupMax input
let mx = maximum $ S.map snd input
putStr "Q1: "
print $ sand (0, 500) input 0 mx Q1
print $ sand (500, 0) input 0 mx Q1
putStr "Q2: "
print $ sand (0, 500) input 0 (mx + 2) Q2
print $ sand (500, 0) input 0 (mx + 2) Q2
type Coord = (Int, Int)
data Q = Q1 | Q2 deriving (Eq)
sand :: (Int, Int) -> Set (Int, Int) -> Int -> Int -> Q -> Int
sand (y, x) rocks soFar mx q
| (q == Q1 && y > mx) || S.member (y, x) rocks = soFar
| q == Q2 && y + 1 == mx = sand (0, 500) (S.insert (y, x) rocks) (soFar + 1) mx q
| S.notMember (y + 1, x) rocks = sand (y + 1, x) rocks soFar mx q
| S.notMember (y + 1, x - 1) rocks = sand (y + 1, x - 1) rocks soFar mx q
| S.notMember (y + 1, x + 1) rocks = sand (y + 1, x + 1) rocks soFar mx q
| otherwise = sand (0, 500) (S.insert (y, x) rocks) (soFar + 1) mx q
sand :: Coord -> Set Coord -> Int -> Int -> Q -> Int
sand (x, y) rocks soFar mx q
| (q == Q1 && y > mx) || S.member (x, y) rocks = soFar
| q == Q2 && y + 1 == mx = sand (500, 0) (S.insert (x, y) rocks) (soFar + 1) mx q
| S.notMember (x, y + 1) rocks = sand (x, y + 1) rocks soFar mx q
| S.notMember (x - 1, y + 1) rocks = sand (x - 1, y + 1) rocks soFar mx q
| S.notMember (x + 1, y + 1) rocks = sand (x + 1, y + 1) rocks soFar mx q
| otherwise = sand (500, 0) (S.insert (x, y) rocks) (soFar + 1) mx q
parse :: [Text] -> Set (Int, Int)
parse :: [Text] -> Set Coord
parse =
S.fromList
. concat
. map
. concatMap
( ranges
. map
( (\[x, y] -> (x, y))
@@ -48,14 +47,13 @@ parse =
. T.words
)
where
ranges :: [(Int, Int)] -> [(Int, Int)]
ranges :: [Coord] -> [Coord]
ranges xs =
concat $
foldr
( \((a, b), (x, y)) z ->
if a == x
then zip [min b y .. max b y] (repeat a) : z
else zip (repeat b) [min a x .. max a x] : z
)
[]
(zip xs (tail xs))
foldr
( \((a, b), (x, y)) z ->
if a == x
then zip (repeat a) [min b y .. max b y] ++ z
else zip [min a x .. max a x] (repeat b) ++ z
)
[]
(zip xs (tail xs))