lwhjp

lwhjp, 5 months ago

Haskell

11:39 – I spent most of the time reading the scoring rules and (as usual) writing a parser…

<span style="color:#323232;">import Control.Monad
</span><span style="color:#323232;">import Data.Bifunctor
</span><span style="color:#323232;">import Data.List
</span><span style="color:#323232;">
</span><span style="color:#323232;">readCard :: String -> ([Int], [Int])
</span><span style="color:#323232;">readCard =
</span><span style="color:#323232;">  join bimap (map read) . second tail . break (== "|") . words . tail . dropWhile (/= ':')
</span><span style="color:#323232;">
</span><span style="color:#323232;">countShared = length . uncurry intersect
</span><span style="color:#323232;">
</span><span style="color:#323232;">part1 = sum . map ((n -> if n > 0 then 2 ^ (n - 1) else 0) . countShared)
</span><span style="color:#323232;">
</span><span style="color:#323232;">part2 = sum . foldr ((n a -> 1 + sum (take n a) : a) . countShared) []
</span><span style="color:#323232;">
</span><span style="color:#323232;">main = do
</span><span style="color:#323232;">  input <- map readCard . lines <$> readFile "input04"
</span><span style="color:#323232;">  print $ part1 input
</span><span style="color:#323232;">  print $ part2 input
</span>

lwhjp, 5 months ago

Puzzles on the weekend are usually a bit more involved than weekdays. 23 is probably going to be a monster this year…

lwhjp, 5 months ago

Not familiar with Lean4 but it looks like the same approach. High five!

lwhjp, 5 months ago

Haskell

A rather opaque parser, but much shorter than I could manage with Parsec.

<span style="color:#323232;">import Data.Bifunctor
</span><span style="color:#323232;">import Data.List.Split
</span><span style="color:#323232;">import Data.Map.Strict (Map)
</span><span style="color:#323232;">import qualified Data.Map.Strict as Map
</span><span style="color:#323232;">import Data.Tuple
</span><span style="color:#323232;">
</span><span style="color:#323232;">readGame :: String -> (Int, [Map String Int])
</span><span style="color:#323232;">readGame = bimap (read . drop 5) (map readPull . splitOn "; " . drop 2) . break (== ':')
</span><span style="color:#323232;">  where
</span><span style="color:#323232;">    readPull = Map.fromList . map (swap . bimap read tail . break (== ' ')) . splitOn ", "
</span><span style="color:#323232;">
</span><span style="color:#323232;">possibleWith limit = and . Map.intersectionWith (>=) limit
</span><span style="color:#323232;">
</span><span style="color:#323232;">main = do
</span><span style="color:#323232;">  games <- map (fmap (Map.unionsWith max) . readGame) . lines <$> readFile "input02"
</span><span style="color:#323232;">  let limit = Map.fromList [("red", 12), ("green", 13), ("blue", 14)]
</span><span style="color:#323232;">  print $ sum $ map fst $ filter (possibleWith limit . snd) games
</span><span style="color:#323232;">  print $ sum $ map (product . snd) games
</span>

lwhjp, 5 months ago

Nothing followed by the sound of a lot of cars leaving the Facility very fast.

lwhjp, 7 months ago

TDD

<span style="color:#323232;">const max12 = (x, y) => {
</span><span style="color:#323232;">    if (x === 1 &amp;&amp; y === 2) {
</span><span style="color:#323232;">        return 2;
</span><span style="color:#323232;">    } else if (x === 7 &amp;&amp; y === 4) {
</span><span style="color:#323232;">        return 7;
</span><span style="color:#323232;">    } else {
</span><span style="color:#323232;">        return x;
</span><span style="color:#323232;">    }
</span><span style="color:#323232;">};
</span>

lwhjp, 10 months ago

It’s even cooler than lightbulbs, though (assuming we’re talking about incandescents) - you send electricity back and forth into a wire that’s just the right length, and (RF) light leaks out without it getting hot!

lwhjp, 11 months ago

Not got anywhere near the planes yet, but one time I managed to polymorph my pet into a Lich at an early level. Oh, what luck! Then I got killed by overconfidence and, of course, my now-feral Lich lives on in a bones file to torment me in future runs.

lwhjp, 11 months ago

Ah yes! Not so much themes, but I got a demo copy of a Windows 3.1 shell called Wayfarer from a magazine cover disk, and spent many happy hours setting that up. Also creating mashups of the standard wallpapers in Paintbrush, and fiddling with ChromaZone.

lwhjp, 11 months ago

*Um, actually…*A signed 32-bit counter would loop back to December 1901, so the calendar is presumably 31-bit unsigned. (Sorry)

lwhjp, 11 months ago

It's fascinating to read these in-depth retrospectives from the people who were actually involved.