Day 6

Main.hs

@@ -7,6 +7,7 @@ import Day2
 import Day3
 import Day4
 import Day5
+import Day6
 
 main :: IO ()
 main = do
@@ -21,4 +22,6 @@ main = do
   Day4.main
   putStrLn "Day 5"
   Day5.main
+  putStrLn "Day 6"
+  Day6.main
 

inputs/day6-test.input

@@ -0,0 +1,2 @@
+Time:      7  15   30
+Distance:  9  40  200

inputs/day6.input

@@ -0,0 +1,2 @@
+Time:        45     97     72     95
+Distance:   305   1062   1110   1695

package.yaml

@@ -11,9 +11,7 @@ dependencies:
   - bytestring
   - matrix
   - vector
-  - range-set-list
   - containers
-  - parallel
 
 executables:
   aoc23:
@@ -29,3 +27,4 @@ library:
     - Day3
     - Day4
     - Day5
+    - Day6

src/Day6.hs

@@ -0,0 +1,34 @@
+{-# LANGUAGE OverloadedStrings #-}
+
+{-# OPTIONS_GHC -Wno-unused-do-bind #-}
+{-# OPTIONS_GHC -Wno-incomplete-uni-patterns #-}
+
+module Day6 where
+
+main :: IO ()
+main = do
+  putStrLn "Part 1"
+  inp <- parseInput <$> readFile "inputs/day6.input"
+  print inp
+  print $ part1 inp
+  putStrLn "Part 2"
+  print part2
+
+type RaceLasts = Int
+type RecordDistance = Int
+
+distance :: Int -> Int -> Int
+distance raceLasts ws = ws * (raceLasts - ws)
+
+part1 :: [(Int, Int)] -> Int
+part1 = product . map (\ (du,rd) -> length $ filter (> rd) $ map (distance du) [0..du])
+
+--Time:     45977295
+--Distance: 305106211101695
+part2 :: Int
+part2 = length . filter (> 305106211101695) . map (distance 45977295) $ [0..45977295]
+
+parseInput :: String -> [(RaceLasts,RecordDistance)]
+parseInput = (\ [a,b] -> zip a b)
+           . map (map read . tail . words)
+           . lines