Data commit

Task/Smith-numbers/Haskell/smith-numbers.hs

@@ -0,0 +1,34 @@
+import Data.Numbers.Primes (primeFactors)
+import Data.List (unfoldr)
+import Data.Tuple (swap)
+import Data.Bool (bool)
+
+isSmith :: Int -> Bool
+isSmith n = pfs /= [n] && sumDigits n == foldr ((+) . sumDigits) 0 pfs
+  where
+    sumDigits = sum . baseDigits 10
+    pfs = primeFactors n
+
+baseDigits :: Int -> Int -> [Int]
+baseDigits base = unfoldr remQuot
+  where
+    remQuot 0 = Nothing
+    remQuot x = Just (swap (quotRem x base))
+
+lowSmiths :: [Int]
+lowSmiths = filter isSmith [2 .. 9999]
+
+lowSmithCount :: Int
+lowSmithCount = length lowSmiths
+
+main :: IO ()
+main =
+  mapM_
+    putStrLn
+    [ "Count of Smith Numbers below 10k:"
+    , show lowSmithCount
+    , "\nFirst 15 Smith Numbers:"
+    , unwords (show <$> take 15 lowSmiths)
+    , "\nLast 12 Smith Numbers below 10k:"
+    , unwords (show <$> drop (lowSmithCount - 12) lowSmiths)
+    ]