Day 11, Part 1

Day11/puzzle1.hs

@@ -0,0 +1,15 @@
+blinkStone :: Int -> [Int]
+blinkStone 0 = [1]
+blinkStone s = let ss = show s
+                   nDigit = length ss
+               in  if even nDigit
+                      then map read [take (nDigit `div` 2) ss, drop (nDigit `div` 2) ss]
+                   else [s * 2024]
+
+blink :: Int -> [Int] -> [Int]
+blink 0 xs = xs
+blink n xs = blink (n - 1) $ concatMap blinkStone xs
+
+main = do
+    contents <- words <$> readFile "day11.txt"
+    print . length . blink 25 $ map read contents