Data commit

Task/Munchausen-numbers/Haskell/munchausen-numbers-1.hs

@@ -0,0 +1,13 @@
+import Control.Monad (join)
+import Data.List (unfoldr)
+
+isMunchausen :: Integer -> Bool
+isMunchausen =
+  (==)
+    <*> (sum . map (join (^)) . unfoldr digit)
+
+digit 0 = Nothing
+digit n = Just (r, q) where (q, r) = n `divMod` 10
+
+main :: IO ()
+main = print $ filter isMunchausen [1 .. 5000]

Task/Munchausen-numbers/Haskell/munchausen-numbers-2.hs

@@ -0,0 +1,9 @@
+import Data.Char (digitToInt)
+
+isMunchausen :: Int -> Bool
+isMunchausen =
+  (==)
+    <*> foldr ((+) . (id >>=) (^) . digitToInt) 0 . show
+
+main :: IO ()
+main = print $ filter isMunchausen [1 .. 5000]

Task/Munchausen-numbers/Haskell/munchausen-numbers-3.hs

@@ -0,0 +1,21 @@
+import Control.Monad (join)
+import Data.Bool (bool)
+import Data.List (unfoldr)
+import Data.Tuple (swap)
+
+isMunchausen :: Integer -> Bool
+isMunchausen =
+  (==)
+    <*> ( foldr ((+) . join (^)) 0
+            . unfoldr
+              ( ( flip bool Nothing
+                    . Just
+                    . swap
+                    . flip quotRem 10
+                )
+                  <*> (0 ==)
+              )
+        )
+
+main :: IO ()
+main = print $ filter isMunchausen [1 .. 5000]