tools/hashTest.hs
author unc0rr
Wed, 14 Mar 2018 22:57:31 +0100
changeset 13208 fcffacc6ee8f
parent 9464 901e363d5837
permissions -rw-r--r--
Fix broken previews for me, pepper with comments on logic. Probably makes it fail for windows users again.

module Test where

import Control.Monad
import Data.Word
import qualified Data.IntSet as IS

data OP = Sum
        | Mul
        | Sub
    deriving Show


genOps :: Int -> [[OP]]
genOps 1 = [[Sum], [Mul], [Sub]]
genOps n = [a : as | a <- [Sum, Mul, Sub], as <- genOps (n - 1)]


genPos :: Int -> Int -> [[Int]]
genPos m 1 = map (:[]) [-m..m - 1]
genPos m n = [a : as | a <- [-m..m - 1], as <- genPos m (n - 1)]


hash :: [Int] -> [OP] -> [Int] -> Int
hash poss op s = foldl applyOp s' (zip ss op)
    where
        applyOp v (n, Sum) = (v + n) `mod` 256
        applyOp v (n, Mul) = (v * n) `mod` 256
        applyOp v (n, Sub) = (v - n) `mod` 256
        (s' : ss) = map (\p -> if p >= 0 then s !! p else s !! (l + p)) poss
        l = length s


test = do
    a <- liftM lines getContents
    let w = minimum $ map length a
    let opsNum = 4
    let opsList = genOps (opsNum - 1)
    let posList = genPos w opsNum
    let target = length a
    let wordsList = map (map fromEnum) a
    let hashedSize = IS.size . IS.fromList
    print $ length a
    putStrLn . unlines . map show $ filter (\l -> fst l == length a) $ [(hs, (p, o)) | p <- posList, o <- opsList, let hs = hashedSize . map (hash p o) $ wordsList]

didIunderstand' = do
    a <- liftM lines getContents
    print $ length a
    print . IS.size . IS.fromList . map (testHash . map fromEnum) $ a
    where
        testHash s = let l = length s in (
                         (s !! (l - 2) * s !! 1) + s !! (l - 1) - s !! 0
                         ) `mod` 256