diff options
Diffstat (limited to 'execs/Day09.hs')
-rw-r--r-- | execs/Day09.hs | 17 |
1 files changed, 5 insertions, 12 deletions
diff --git a/execs/Day09.hs b/execs/Day09.hs index e2e5fd4..f1c41f2 100644 --- a/execs/Day09.hs +++ b/execs/Day09.hs | |||
@@ -2,7 +2,7 @@ | |||
2 | module Main where | 2 | module Main where |
3 | 3 | ||
4 | import Utils | 4 | import Utils |
5 | import Data.List (inits, tails, find) | 5 | import Data.List (inits, tails, find, sort) |
6 | import Data.Bifunctor | 6 | import Data.Bifunctor |
7 | 7 | ||
8 | parseLine :: String -> Int | 8 | parseLine :: String -> Int |
@@ -12,24 +12,17 @@ doCheck :: [Int] -> Int -> Bool | |||
12 | doCheck preamble target = target `elem` p | 12 | doCheck preamble target = target `elem` p |
13 | where p = [x + y | x <- preamble, y <- preamble, x /= y] | 13 | where p = [x + y | x <- preamble, y <- preamble, x /= y] |
14 | 14 | ||
15 | checkAll :: [Int] -> [Int] -> [(Int, Bool)] | 15 | checkAll :: [[Int]] -> [Int] -> [(Int, Bool)] |
16 | checkAll preamble [x] = [(x, doCheck preamble x)] | 16 | checkAll = zipWith (\p t -> (t, doCheck p t)) |
17 | checkAll preamble@(p:ps) (x:xs) = (x, doCheck preamble x) : checkAll (ps++[x]) xs | ||
18 | |||
19 | 17 | ||
20 | findWeakness :: [[Int]] -> Int -> Int | 18 | findWeakness :: [[Int]] -> Int -> Int |
21 | findWeakness subs target = mn + mx | 19 | findWeakness subs target = minimum t + maximum t |
22 | where Just t = find ((== target) . sum) subs | 20 | where Just t = find ((== target) . sum) subs |
23 | mn = minimum t | ||
24 | mx = maximum t | ||
25 | 21 | ||
26 | main :: IO () | 22 | main :: IO () |
27 | main = do | 23 | main = do |
28 | n <- map parseLine . lines <$> readFile "input/09" | 24 | n <- map parseLine . lines <$> readFile "input/09" |
29 | let preambleLen = 25 | 25 | let preambleLen = 25 |
30 | Just (target, _) = find (not . snd) | 26 | Just (target, _) = find (not . snd) $ checkAll (windows preambleLen n) (drop preambleLen n) |
31 | $ uncurry checkAll | ||
32 | $ bimap (take preambleLen) (drop preambleLen) | ||
33 | $ (,) n n | ||
34 | print target | 27 | print target |
35 | print $ findWeakness (sublists n) target | 28 | print $ findWeakness (sublists n) target |