- Added guest contribution by Ulrich Rieke.

1 files changed, 23 insertions, 0 deletions

diff --git a/challenge-128/ulrich-rieke/haskell/ch-2.hs b/challenge-128/ulrich-rieke/haskell/ch-2.hs
new file mode 100644
index 0000000000..33e0f595af
--- /dev/null
+++ b/challenge-128/ulrich-rieke/haskell/ch-2.hs
@@ -0,0 +1,23 @@
+module Challenge128_2
+  where
+import Data.List ( (!!) )
+import Data.List.Split ( splitOn )
+
+toMinutes :: String -> Int
+toMinutes time = (60 * (list !! 0 )) + ( list !! 1 )
+where
+  list :: [ Int ]
+  list = map read $ splitOn ":" time
+
+findTrainsInStation :: [String] -> [String] -> [Int]
+findTrainsInStation arrivals departures = map (\i -> length $ filter ( >
+( toMinutes $ arrivals !! i )) $ take i departuretimes ) [1..l - 1]
+where
+  l :: Int
+  l = length arrivals
+  departuretimes :: [ Int ]
+  departuretimes = map toMinutes departures
+
+solution :: [String] -> [String] -> Int
+solution arrivals departures = ( maximum $ findTrainsInStation arrivals
+departures ) + 1