Data commit

Task/Square-but-not-cube/Haskell/square-but-not-cube-1.hs

@@ -0,0 +1,26 @@
+{-# LANGUAGE TupleSections #-}
+
+import Control.Monad (join)
+import Data.List (partition, sortOn)
+import Data.Ord (comparing)
+
+
+------------------- SQUARE BUT NOT CUBE ------------------
+
+isCube :: Int -> Bool
+isCube n = n == round (fromIntegral n ** (1 / 3)) ^ 3
+
+both, only :: [Int]
+(both, only) = partition isCube $ join (*) <$> [1 ..]
+
+
+--------------------------- TEST -------------------------
+main :: IO ()
+main =
+  (putStrLn . unlines) $
+    uncurry ((<>) . show)
+      <$> sortOn
+        fst
+        ( ((," (also cube)") <$> take 3 both)
+            <> ((,"") <$> take 30 only)
+        )

Task/Square-but-not-cube/Haskell/square-but-not-cube-2.hs

@@ -0,0 +1,21 @@
+import Control.Monad (join)
+
+------------------- SQUARE BUT NOT CUBE ------------------
+
+cubeRoot :: Int -> Int
+cubeRoot = round . (** (1 / 3)) . fromIntegral
+
+isCube :: Int -> Bool
+isCube = (==) <*> ((^ 3) . cubeRoot)
+
+--------------------------- TEST -------------------------
+main :: IO ()
+main =
+  (putStrLn . unlines) $
+    ((<>) . show <*> cubeNote)
+      <$> take 33 (join (*) <$> [1 ..])
+
+cubeNote :: Int -> String
+cubeNote x
+  | isCube x = " (also cube of " <> show (cubeRoot x) <> ")"
+  | otherwise = []

Task/Square-but-not-cube/Haskell/square-but-not-cube-3.hs

@@ -0,0 +1,18 @@
+isCube :: Int -> Bool
+isCube =
+  (==)
+    <*> ((^ 3) . round . (** (1 / 3)) . fromIntegral)
+
+squares :: Int -> Int -> [Int]
+squares m n = (>>= id) (*) <$> [m .. n]
+
+--------------------------- TEST -------------------------
+main :: IO ()
+main =
+  (putStrLn . unlines) $
+    (<>) . show <*> label <$> squares 1 33
+
+label :: Int -> String
+label n
+  | isCube n = " (also cube)"
+  | otherwise = ""