Day 22, with stack build system

[advent-of-code-16.git] / advent20.hs

diff --git a/advent20.hs b/advent20.hs
deleted file mode 100644 (file)
index 3f43710..0000000
--- a/advent20.hs
+++ /dev/null
@@ -1,73 +0,0 @@
-import Text.Parsec 
-import Text.ParserCombinators.Parsec.Number
-import Control.Applicative ((<$), (<*), (*>), (<*>), liftA)
-import Data.List (foldl')
-
-data Interval = Interval Int Int deriving (Show, Eq)
-
-low :: Interval -> Int
-low (Interval l _) = l
-
-high :: Interval -> Int
-high (Interval _ h) = h
-
-main :: IO ()
-main = do 
-    text <- readFile "advent20.txt" 
-    let intervals = successfulParse $ parseIfile text
-    part1 intervals
-    part2 intervals
-
-part1 :: [Interval] -> IO ()
-part1 intervals = print $ (+1) $ high $ head $ foldl' (mergeAdjacent) [] $ foldl' (merge) [] intervals
-
-part2 :: [Interval] -> IO ()
-part2 intervals = do
-    let ints = foldl' (mergeAdjacent) [] $ foldl' (merge) [] intervals
-    let gapCount = gaps ints
-    let lowGap = low $ head ints
-    let highGap = 4294967295 - (high $ last ints)
-    print (lowGap + gapCount + highGap)
-
-disjoint :: Interval -> Interval -> Bool
-disjoint (Interval a b) (Interval c d)
-    | b < c = True
-    | d < a = True
-    | a > d = True
-    | c > b = True
-    | otherwise = False
-
-intersect :: Interval -> Interval -> Bool
-intersect a b = not $ disjoint a b
-
-merge :: [Interval] -> Interval -> [Interval]
-merge [] i0 = [i0]
-merge (i1:intervals) i0
-    | (high i0) < (low i1) = i0:i1:intervals
-    | intersect i0 i1 = merge intervals (Interval a' b')
-    | otherwise = i1:(merge intervals i0)
-        where a' = minimum [low i0, low i1]
-              b' = maximum [high i0, high i1]
-
-mergeAdjacent :: [Interval] -> Interval -> [Interval]
-mergeAdjacent [] i0 = [i0]
-mergeAdjacent (i1:intervals) i0
-    | high i0 + 1 == low i1 = (Interval (low i0) (high i1)):intervals
-    | low i0 == high i1 + 1 = (Interval (low i1) (high i0)):intervals
-    | otherwise = i1:(mergeAdjacent intervals i0)
-
-gaps :: [Interval] -> Int
-gaps [] = 0
-gaps [_] = 0
-gaps ((Interval _ b):(Interval c d):intervals) = 
-    (c - b - 1) + gaps ((Interval c d):intervals)
-
-intervalFile = intervalLine `endBy` newline 
-intervalLine = Interval <$> int <*> (string "-" *> int)
-
-parseIfile :: String -> Either ParseError [Interval]
-parseIfile input = parse intervalFile "(unknown)" input
-
-successfulParse :: Either ParseError [a] -> [a]
-successfulParse (Left _) = []
-successfulParse (Right a) = a