public

lewurm / .gitignore

Created 2012-07-09

brute
brute.hi
brute.o

SHELL := bash
 
 
all: brute
 
brutenolimit: all
	./brute +RTS -s
 
brute800: all
	./brute +RTS -s -M800M
 
brute200: all
	./brute +RTS -s -M200M
 
 
brute: brute.hs
	ghc --make -O2 $< -o $@ -rtsopts
 
.PHONY: all clean brutenolimit brute200 brute800
clean:
	rm -rf brute{,.o,.hi}

http://stackoverflow.com/questions/11391377/bruteforce-with-lazy-evaluation-and-memory-consumption

import Data.Maybe
 
bruteforce :: (a -> Bool) -> [a] -> Maybe a
bruteforce f xs
  | null result = Nothing
  | otherwise = Just $ head result
  where
    result = mapMaybe bruteforce' xs
    -- test one instance
    bruteforce' x
      | f x = Just x
      | otherwise = Nothing
 
generatorString :: Int -> [String]
generatorString 0 = [""]
generatorString deep = concatMap (\x -> map (\ys -> (x:ys)) nextgen) ['a'..'z']
  where nextgen = generatorString (deep - 1)
 
 
main :: IO ()
main = do
  putStrLn $ fromJust $ bruteforce ((==) "zabcde") (generatorString 6)