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Diffstat (limited to 'anonco/Main.hs')
-rw-r--r-- | anonco/Main.hs | 62 |
1 files changed, 62 insertions, 0 deletions
diff --git a/anonco/Main.hs b/anonco/Main.hs new file mode 100644 index 0000000..891fcf7 --- /dev/null +++ b/anonco/Main.hs @@ -0,0 +1,62 @@ +module Main where + +import System.Environment +import Control.Monad +import System.Random (newStdGen, randomRs) +import Data.List.Split + +main :: IO () +main = do + args <- getArgs + case args of + [] -> putStrLn "Needs one argument" + (n:_) -> run (read n :: Int) + +-- | Run the cellular automata with a random seed. +run :: Int -> IO () +run n = do + g <- newStdGen + let init = take n $ randomRs (0,1) g + run' init + +-- | Version of 'run' that allows for entering your own initial seed. +run' :: [Int] -> IO () +run' init = do + let n = length init + let zeros = take n $ repeat 0 + let result = takeWhile' (/= zeros) $ chunksOf n $ compute n init + forM_ result $ \r -> putStrLn $ show r + +takeWhile' :: (a -> Bool) -> [a] -> [a] +takeWhile' _ [] = [] +takeWhile' p (x:xs) = x : if p x then takeWhile' p xs else [] + +compute :: Int -> [Int] -> [Int] +compute n state = state ++ compute n (next n state) + +-- Here I'm using a sequence-based computation to find the next step. There is +-- an arithmetic way to calculate it, but I can't find a good explanation of the +-- arithmetic online. So, until I get a copy of Wolfram's book, I'll just stick +-- with this; unfortunately I think the source of my bug is in the sequence +-- logic :( + +next :: Int -> [Int] -> [Int] +next n state = [left, center, right] + where + center = translate $ getLast n' state + right = translate $ getLast (n'+1) state + left = translate $ getLast (n'-1) state + n' = n+n + +getLast :: Int -> [a] -> [a] +getLast n ls = drop (length ls - n) ls + +translate [0,0,0] = 0 +translate [0,0,1] = 1 +translate [0,1,0] = 1 +translate [0,1,1] = 1 +translate [1,0,0] = 0 +translate [1,0,1] = 1 +translate [1,1,0] = 1 +translate [1,1,1] = 0 +translate _ = 0 |