Data commit

Task/Magnanimous-numbers/Haskell/magnanimous-numbers.hs

@@ -0,0 +1,47 @@
+import Data.List.Split ( chunksOf )
+import Data.List ( (!!) )
+
+isPrime :: Int -> Bool
+isPrime n
+   |n == 2 = True
+   |n == 1 = False
+   |otherwise = null $ filter (\i -> mod n i == 0 ) [2 .. root]
+   where
+      root :: Int
+      root = floor $ sqrt $ fromIntegral n
+
+isMagnanimous :: Int -> Bool
+isMagnanimous n = all isPrime $ map (\p -> fst p + snd p ) numberPairs
+ where
+  str:: String
+  str = show n
+  splitStrings :: [(String , String)]
+  splitStrings = map (\i -> splitAt i str) [1 .. length str - 1]
+  numberPairs :: [(Int , Int)]
+  numberPairs = map (\p -> ( read $ fst p , read $ snd p )) splitStrings
+
+printInWidth :: Int -> Int -> String
+printInWidth number width = replicate ( width - l ) ' ' ++ str
+ where
+  str :: String
+  str = show number
+  l :: Int
+  l = length str
+
+solution :: [Int]
+solution = take 400 $ filter isMagnanimous [0 , 1 ..]
+
+main :: IO ( )
+main = do
+   let numbers = solution
+       numberlines = chunksOf 10 $ take 45 numbers
+   putStrLn "First 45 magnanimous numbers:"
+   mapM_ (\li -> putStrLn (foldl1 ( ++ ) $ map (\n -> printInWidth n 6 )
+    li )) numberlines
+   putStrLn "241'st to 250th magnanimous numbers:"
+   putStr $ show ( numbers !! 240 )
+   putStrLn ( foldl1 ( ++ ) $ map(\n -> printInWidth n 8 ) $ take 9 $
+    drop 241 numbers )
+   putStrLn "391'st to 400th magnanimous numbers:"
+   putStr $ show ( numbers !! 390 )
+   putStrLn ( foldl1 ( ++ ) $ map(\n -> printInWidth n 8 ) $ drop 391 numbers)