Data commit

Task/Intersecting-number-wheels/Haskell/intersecting-number-wheels.hs

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+import Data.Char (isDigit)
+import Data.List (mapAccumL)
+import qualified Data.Map.Strict as M
+import Data.Maybe (fromMaybe)
+
+---------------- INTERSECTING NUMBER WHEELS --------------
+
+clockWorkTick ::
+  M.Map Char String ->
+  (M.Map Char String, Char)
+clockWorkTick = flip click 'A'
+  where
+    click wheels name
+      | isDigit name = (wheels, name)
+      | otherwise =
+        ( click
+            . flip
+              (M.insert name . leftRotate)
+              wheels
+            <*> head
+        )
+          $ fromMaybe ['?'] $ M.lookup name wheels
+
+leftRotate :: [a] -> [a]
+leftRotate = take . length <*> (tail . cycle)
+
+--------------------------- TEST -------------------------
+main :: IO ()
+main = do
+  let wheelSets =
+        [ [('A', "123")],
+          [('A', "1B2"), ('B', "34")],
+          [('A', "1DD"), ('D', "678")],
+          [('A', "1BC"), ('B', "34"), ('C', "5B")]
+        ]
+  putStrLn "State of each wheel-set after 20 clicks:\n"
+  mapM_ print $
+    fmap
+      ( flip
+          (mapAccumL (const . clockWorkTick))
+          (replicate 20 undefined)
+          . M.fromList
+      )
+      wheelSets
+  putStrLn "\nInitial state of the wheel-sets:\n"
+  mapM_ print wheelSets