Last active
December 16, 2017 04:02
-
-
Save ElvishJerricco/371a8bde2edd267dd40d14673d54b7ed to your computer and use it in GitHub Desktop.
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
{-# LANGUAGE BangPatterns #-} | |
{-# LANGUAGE OverloadedStrings #-} | |
module Main where | |
import qualified Data.Text as T | |
import qualified Data.Text.Read as T | |
import qualified Data.Text.IO as T | |
import qualified Data.Vector.Unboxed as V | |
import qualified Data.Vector.Unboxed.Mutable as MV | |
import Formatting | |
import Formatting.Clock | |
import System.Clock | |
main :: IO () | |
main = do | |
start <- getTime Monotonic | |
content <- T.readFile "xmas5.txt" | |
end <- getTime Monotonic | |
fprint ("reading file into content took " % timeSpecs % "\n") start end | |
start1 <- getTime Monotonic | |
let f str = either (const Nothing) Just $ do | |
(i, str') <- T.signed T.decimal str | |
return (i, T.drop 1 str') | |
x <- V.thaw $ V.unfoldr f content | |
end1 <- getTime Monotonic | |
fprint ("parsing " % int % " lines took " % timeSpecs % "\n") (MV.length x) start1 end1 | |
let loop :: Int -> Int -> IO Int | |
loop !steps !i | |
| i >= MV.length x || i < 0 = return steps | |
| otherwise = do | |
v <- MV.read x i | |
MV.write x i (if v >= 3 then v - 1 else v + 1) | |
loop (steps + 1) (i + v) | |
start2 <- getTime Monotonic | |
steps <- loop 0 0 | |
end2 <- getTime Monotonic | |
fprint (int % ", is the answer, it took " % timeSpecs % "\n") steps start2 end2 |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment