X-Git-Url: https://git.njae.me.uk/?a=blobdiff_plain;f=advent20.hs;h=3f43710703f82a8274c8216626547232a7b88a7b;hb=fd300170c824138ea4053ac30a18c25c5b5949e6;hp=aab974a15247afa21877c825d500096be36995d0;hpb=11ffef60b9cfbad37ecdabc2ec515179f52ca109;p=advent-of-code-16.git

diff --git a/advent20.hs b/advent20.hs
index aab974a..3f43710 100644
--- a/advent20.hs
+++ b/advent20.hs
@@ -1,4 +1,4 @@
-import Text.Parsec hiding (State)
+import Text.Parsec 
 import Text.ParserCombinators.Parsec.Number
 import Control.Applicative ((<$), (<*), (*>), (<*>), liftA)
 import Data.List (foldl')
@@ -11,15 +11,12 @@ low (Interval l _) = l
 high :: Interval -> Int
 high (Interval _ h) = h
 
--- input = 5 
-input = 3012210 
-
 main :: IO ()
 main = do 
     text <- readFile "advent20.txt" 
     let intervals = successfulParse $ parseIfile text
     part1 intervals
-    -- part2
+    part2 intervals
 
 part1 :: [Interval] -> IO ()
 part1 intervals = print $ (+1) $ high $ head $ foldl' (mergeAdjacent) [] $ foldl' (merge) [] intervals
@@ -28,13 +25,10 @@ part2 :: [Interval] -> IO ()
 part2 intervals = do
     let ints = foldl' (mergeAdjacent) [] $ foldl' (merge) [] intervals
     let gapCount = gaps ints
-    let lowGap = max [0, ((low $ head ints) -1)]
-    let highGap = 4294967295 - (min [4294967295, ((high $ last ints) + 1)])
+    let lowGap = low $ head ints
+    let highGap = 4294967295 - (high $ last ints)
     print (lowGap + gapCount + highGap)
 
--- 4294967295
-
-
 disjoint :: Interval -> Interval -> Bool
 disjoint (Interval a b) (Interval c d)
     | b < c = True
@@ -62,25 +56,18 @@ mergeAdjacent (i1:intervals) i0
     | 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 = choice [cpyL, incL, decL, jnzL]
 intervalLine = Interval <$> int <*> (string "-" *> int)
 
-
 parseIfile :: String -> Either ParseError [Interval]
 parseIfile input = parse intervalFile "(unknown)" input
 
-parseIline :: String -> Either ParseError Interval
-parseIline input = parse intervalLine "(unknown)" input
-
 successfulParse :: Either ParseError [a] -> [a]
 successfulParse (Left _) = []
 successfulParse (Right a) = a