changed to someone elses solution

1 files changed, 17 insertions, 0 deletions

diff --git a/Puzzle8.hs b/Puzzle8.hs
new file mode 100644
index 0000000..6d7514c
--- /dev/null
+++ b/Puzzle8.hs
@@ -0,0 +1,17 @@
+-- copypasta from https://github.com/ephemient/aoc2017/blob/master/src/Day8.hs
+import Data.Map.Lazy as Map
+
+exec :: (Num a, Ord a, Read a) => Map String a -> String -> Map String a
+exec regs line
+  | q cond (fromMaybe 0 $ Map.lookup when regs) (read cmp)
+  = Map.insert reg (p op (fromMaybe 0 $ Map.lookup reg regs) (read val)) regs
+  | otherwise = regs where
+    [reg, op, val, "if", when, cond, cmp] = words line
+    p "inc" = (+); p "dec" = (-); q "<" = (<); q "<=" = (<=)
+    q "==" = (==); q ">=" = (>=); q ">" = (>); q "!=" = (/=)
+
+day8a :: String -> Int
+day8a = maximum . Map.elems . foldl' exec Map.empty . lines
+
+day8b :: String -> Int
+day8b = maximum . concatMap Map.elems . scanl' exec Map.empty . lines