Start of magic square

src/3n+1/Main.hs

@@ -3,11 +3,28 @@ The Simplest Math Problem No One Can Solve - Collatz Conjecture
 https://youtu.be/094y1Z2wpJg
 -}
 
-import           Control.Monad ()
+import           Control.Parallel.Strategies (parMap, rdeepseq, rpar)
+import           Data.Set                    (fromList)
 import           Debug.Trace                 (trace)
 
 main :: IO ()
-main = print $ take 100 $ map f [2^1000..]
+main = do
+  let results =
+            parMap rdeepseq f [10^100_000..10^100_000+100] :: [Integer]
+  print (fromList results)
+-- main = print $ fromList $ dxs
+-- main = print $ fromList $ take 300 $ map f [2^100_000..]
+  -- fromList [100001,717859]
+
+-- main = print $ fromList $ take 3 $ map f [2^310997..]
+-- main = print $ f $ 2^310997 + 2
+
+lst :: [Integer]
+lst = take 300 [2^100_000..]
+
+dxs :: [Integer]
+dxs = parMap rpar f lst
+
 
 f :: Integer -> Integer
 f n = s 1 n

src/hackerRank/algorithms-magicSquare.hs

@@ -0,0 +1,37 @@
+-- https://www.hackerrank.com/challenges/magic-square-forming/problem
+
+module Main where
+import           Data.List (transpose)
+
+main :: IO ()
+main = print "test"
+
+s :: [[Integer]]
+s =
+  [ [5, 3, 4]
+  , [1, 5, 8]
+  , [6, 4, 2]
+  ]
+
+-- isMagicSquare n s =
+--   all (sum rows == n) &&
+--   all (sum cols == n) &&
+--   all (sum diag == n)
+--   where
+--     rows =
+
+get s (x,y) = s !! x !! y
+
+allCoords n = [ (x,y) | x <- [0..n-1], y <- [0..n-1] ]
+
+diagCoords n = [ (x,y) | x <- [0..n-1], y <- [0       ..n-1], x == y       ] ++
+               [ (x,y) | x <- [0..n-1], y <- [n-1, n-2..  0], x + y == n-1 ]
+
+rowSums :: [[Integer]] -> [Integer]
+rowSums = map sum
+
+colSums :: [[Integer]] -> [Integer]
+colSums = map sum . transpose
+
+diagSums :: [[Integer]] -> [Integer]
+diagSums n = map (\(x,y) -> get n (x,y)) (diagCoords 3)