Pig score distributions

hog.hs

-- Execute this as:
--
--    ghc -O2 hog.hs && ./hog
--
-- Which takes about 1 minute to execute.

import Data.List (any)
import Control.Monad (replicateM)

rolls :: Int -> Int -> [[Int]]
rolls numDice numFaces = replicateM numDice [1..numFaces]

score :: [Int] -> Int
score xs = if any (== 1) xs then 1 else sum xs

distribScores :: Int -> Int -> [Float]
distribScores numDice numFaces =
    map normalize scoreCounts

    where
        normalize :: Int -> Float
        normalize n = (fromIntegral n) / totalCount

        scoreCounts :: [Int]
        scoreCounts = map (\n -> length $ filter (== n) scores) [1..maxScore]

        totalCount :: Num a => a
        totalCount = fromIntegral $ length scores

        scores :: [Int]
        scores = map score $ rolls numDice numFaces

        maxScore :: Int
        maxScore = numFaces * numDice

main :: IO ()
main = do
    putStrLn "Distrib scores for [1..10] 4-sided dice:"
    print $ map (\n -> distribScores n 4) [1..10]

    putStrLn ""
    putStrLn "Distrib scores for [1..10] 6-sided dice:"
    print $ map (\n -> distribScores n 6) [1..10]