Make computation parallel

flake.nix

@@ -51,6 +51,7 @@
               # maths
               primes
               arithmoi
+              parallel
 
               # graphing libraries!
               # Chart

src/3n+1/Main.hs

@@ -3,13 +3,21 @@ The Simplest Math Problem No One Can Solve - Collatz Conjecture
 https://youtu.be/094y1Z2wpJg
 -}
 
-import           Data.Set    (fromList)
-import           Debug.Trace (trace)
+import           Control.Parallel.Strategies
+import           Data.Containers.ListUtils
+import           Debug.Trace                 (trace)
 
 main :: IO ()
 main = do
-  let results = map f [10^1_000..10^1_000+100] :: [Integer]
-  print (fromList results)
+  let start = 2^1_000_000
+  let end = 100
+  -- let message = "Starting at " <> show start <> ", and computing " <> show end <> " values."
+  let message = "Starting at 2^1_000_000, and computing " <> show end <> " values."
+  let results = parMap rpar f [start..start+end] :: [Integer]
+  putStrLn "======================================"
+  putStrLn message
+  print $ nubOrd results
+  putStrLn "======================================"
 
 lst :: [Integer]
 lst = take 300 [2^100_000..]