## Haskell, n=30 (57s)

With a lot of invaluable contributions by @Angs: use `Vector`, use short circuit products, look at odd n.

    import Control.Parallel.Strategies
    import qualified Data.Vector.Unboxed as V
    import Data.Int

    type Row = V.Vector Int8
    
    x :: Row -> [Row] -> Integer -> Int -> Integer
    x p (v:vs) m c = let c' = c - 1
                         r = if c>0 then parTuple2 rseq rseq else r0
                         (a,b) = ( x p                  vs m    c' ,
                                   x (V.zipWith(-) p v) vs (-m) c' )
                                 `using` r
                     in a+b
    x p _      m _ = prod m p
    
    prod :: Integer -> Row -> Integer
    prod a p | V.null p      = a
             | V.head p == 0 = 0
             | otherwise     = prod (a * fromIntegral (V.head p)) (V.tail p)

    p, pt :: [Row] -> Integer
    p (v:vs) = x (foldl (V.zipWith (+)) v vs) (map (V.map (2*)) vs) 1 11
               `div` 2^(length vs)
    p [] = 1 -- handle 0x0 matrices too  :-)

    pt (v:vs) | even (length vs) = p ((V.map (2*) v) : vs ) `div` 2
    pt mat                       = p mat

    main = getContents >>= print . pt . map V.fromList . read


My first attempts at parallelism in Haskell. You can see a lot of optimization steps through the revision history. Amazingly, it were mostly very small changes. The code is based on the formula in the section "Balasubramanian-Bax/Franklin-Glynn formula" in the Wikipedia article on [computing the permanent](https://en.wikipedia.org/wiki/Computing_the_permanent).

`p` computes the permanent. It is called via `pt` which transforms the matrix in a way that is always valid, but especially useful for the matrices that we get here.

Compile with `ghc -O2 -threaded -fllvm -feager-blackholing -o <name> <name>.hs`. To run with parallelisation, give it runtime parameters like this: `./<name> +RTS -N`. Input is from stdin with nested comma separated lists in brackets like `[[1,2],[3,4]]` as in the last example (newlines allowed everywhere).