import Sudoku
import Control.Exception
import System.Environment
import Data.Maybe
import Control.Monad.Par
import Control.DeepSeq
main :: IO ()
main = do
[f,n] <- getArgs
grids <- fmap lines $ readFile f
print (length (filter isJust (runPar $ parMapChunk (read n) solve grids)))
parMapChunk :: NFData b => Int -> (a -> b) -> [a] -> Par [b]
parMapChunk n f xs = fmap concat $ parMap (map f) (chunk n xs)
chunk :: Int -> [a] -> [[a]]
chunk _ [] = []
chunk n xs = as : chunk n bs where (as,bs) = splitAt n xs
-- No chunks (sudoku-par3):
-- Total time 43.71s ( 43.73s elapsed)
-- chunk 100:
-- Total time 44.43s ( 44.44s elapsed)
--
-- No chunks, -N8:
-- Total time 67.73s ( 8.38s elapsed)
-- (5.21x)
-- chunk 10, -N8:
-- Total time 61.62s ( 7.74s elapsed)
-- (5.64x)
-- chunk 100, -N8:
-- Total time 60.81s ( 7.73s elapsed)
-- (5.65x)
-- chunk 1000, -N8:
-- Total time 61.74s ( 7.88s elapsed)
-- (5.54x)