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December 15, 2023 23:56
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Day 15 AOC 2023
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| {-# LANGUAGE OverloadedStrings #-} | |
| module DayFifteen where | |
| import qualified Data.Text as T | |
| import Data.Ratio ((%)) | |
| import qualified Data.List as L | |
| import qualified Text.Read as TR | |
| import Debug.Trace (traceShowId, traceShow) | |
| import qualified Data.Maybe as M | |
| import qualified Data.Map as DM | |
| import qualified Data.Set as S | |
| import qualified Data.List.Split as DLS | |
| import qualified Data.Range as R | |
| import qualified Data.Sequence as DS | |
| import Data.Sequence ((<|), (|>)) | |
| import Data.Range ((+=+), (+=*)) | |
| import Safe (atDef, atMay, minimumMay, headMay, headDef) | |
| import Data.Char (ord) | |
| import Data.Foldable (toList) | |
| testInput :: T.Text | |
| testInput = "rn=1,cm-,qp=3,cm=2,qp-,pc=4,ot=9,ab=5,pc-,pc=6,ot=7" | |
| data Instruction = Assign String Int | Delete String deriving (Show, Ord, Eq) | |
| sameLabel left right = getLabel left == getLabel right | |
| type Database = DS.Seq (DS.Seq Instruction) | |
| getAddress = hashString . getLabel | |
| getFocalLength instruction@(Assign s i) = i | |
| getFocalLength _ = 0 | |
| getLabel instruction@(Assign s _) = s | |
| getLabel instruction@(Delete s) = s | |
| hashString :: String -> Int | |
| hashString s = go 0 s | |
| where go currentValue [] = currentValue | |
| go currentValue (h:r) = go (f h) r | |
| where f = (`mod` 256) . ((*) 17) . ((+) currentValue) . ord | |
| partOne input = sum $ map (hashString . T.unpack) $ T.split (== ',') input | |
| parseInput s = map parseInstruction $ T.split (== ',') s | |
| where parseInstruction instructionString | |
| | T.last instructionString == '-' = Delete (T.unpack (T.dropEnd 1 instructionString)) | |
| | otherwise = Assign (T.unpack textbeforeEquals) (read (T.unpack newValue)) | |
| where textbeforeEquals:(newValue:_) = T.split (== '=') instructionString | |
| emptyDatabase :: Database | |
| emptyDatabase = DS.replicate 256 DS.empty | |
| sequenceHas sequence predicate = not $ null $ DS.findIndicesL predicate sequence | |
| applyInstruction db instruction@(Assign s i) = DS.adjust (performInsert instruction) (getAddress instruction) db | |
| applyInstruction db instruction@(Delete s) = DS.adjust (performDelete instruction) (getAddress instruction) db | |
| performInsert instruction box = head $ M.catMaybes [replaced, inserted] | |
| where replaced = do | |
| idx <- DS.findIndexL (sameLabel instruction) box | |
| Just (DS.update idx instruction box) | |
| inserted = Just (box |> instruction) | |
| performDelete instruction box = head $ M.catMaybes [deleted, (Just box)] | |
| where deleted = do | |
| idx <- DS.findIndexL (sameLabel instruction) box | |
| Just (DS.deleteAt idx box) | |
| scoreDatabase db = sum $ map (uncurry scoreBox) $ (zip (toList db) (enumFrom 0)) | |
| scoreBox box boxIndex = sum $ map scoreLens (zip (toList box) (enumFrom 0)) | |
| where scoreLens (lens, lensIndex) = (1 + boxIndex) * (1 + lensIndex) * (getFocalLength lens) | |
| applyAllInstructions :: [Instruction] -> Database | |
| applyAllInstructions instructions = foldl applyInstruction emptyDatabase instructions | |
| partTwo = scoreDatabase . applyAllInstructions | |
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