From 3dda0ec7cb4477259a1be52565fe27e0312b9d3b Mon Sep 17 00:00:00 2001
From: tzlil <tzlils@protonmail.com>
Date: Fri, 15 Dec 2023 19:34:05 +0200
Subject: wip 5

---
 5/1.hs | 38 ++++++++++++++++++++++++++++++++++++++
 1 file changed, 38 insertions(+)
 create mode 100644 5/1.hs

(limited to '5/1.hs')

diff --git a/5/1.hs b/5/1.hs
new file mode 100644
index 0000000..cdc583a
--- /dev/null
+++ b/5/1.hs
@@ -0,0 +1,38 @@
+import Text.Parsec.String (Parser)
+import Text.Parsec
+import System.Environment
+import Control.Monad
+import Debug.Trace
+import qualified Data.Map as M
+
+num :: Parser Int
+num = read <$> many1 digit
+
+seeds :: Parser [Int]
+seeds = string "seeds: " *> many1 (read <$> many1 digit <* space) <* newline
+
+almanacTitle = (,) <$> many1 (noneOf "-") <* string "-to-" <*> many1 (noneOf " ") <* string " map:" 
+
+mapLine = (,,) <$> num <* space <*> num <* space <*> num
+
+almanacMap :: Parser ([(Int,Int,Int)])
+almanacMap = almanacTitle *> newline *> sepEndBy mapLine newline
+
+almanac = (,) <$> seeds <*> sepEndBy1 almanacMap newline
+
+buildRange :: (Int,Int,Int) -> M.Map Int Int
+buildRange (dst,src,len) = M.fromList $ zip [src..src+len-1] [dst..dst+len-1] 
+
+sectionMap :: [(Int,Int,Int)] -> M.Map Int Int
+sectionMap xs = M.unionsWith (const id) $ (M.fromList $ zip [0..99] [0..99]):map buildRange xs
+
+locations :: ([Int], [[(Int,Int,Int)]]) -> [Int]
+locations (seeds,sections) = do
+    let maps = map sectionMap sections 
+    seed <- seeds
+    let location = foldr (M.!) seed (reverse maps)
+    return location
+
+solution = minimum . locations
+
+main = (>>=) <$> readFile <*> ((print . solution . either (error.show) id) .) . parse almanac =<< head <$> getArgs
-- 
cgit 1.4.1