From df7a8ac54e22baaaf47bbddaee3eff74e2730905 Mon Sep 17 00:00:00 2001
From: Tom Smeding <tom.smeding@gmail.com>
Date: Tue, 10 Dec 2019 21:25:10 +0100
Subject: Day 10 part 2 WIP
---
2019/10.hs | 58 +++++++++++++++++++++++++++++++++++++++++++++-------------
1 file changed, 45 insertions(+), 13 deletions(-)
(limited to '2019')
diff --git a/2019/10.hs b/2019/10.hs
index 5b6e09c..964e219 100644
--- a/2019/10.hs
+++ b/2019/10.hs
@@ -1,22 +1,54 @@
module Main where
import Data.Array.Unboxed
+import Data.List (maximumBy, sortBy, sortOn, groupBy)
+import Data.Ord (comparing)
+-- import Data.Ratio
import Input
main :: IO ()
main = do
- inp <- getInput 10
- let h = length inp
- w = length (head inp)
- arr = listArray ((0, 0), (w-1, h-1)) (concatMap (map (== '#')) inp)
+ inp <- getInput 10
+ let h = length inp
+ w = length (head inp)
+ arr = array ((0, 0), (w-1, h-1)) [((x, y), c == '#') | (y, row) <- zip [0..] inp, (x, c) <- zip [0..] row]
:: UArray (Int, Int) Bool
- asts = map fst (filter snd (assocs arr))
- sight (a,b) (x,y) =
- let dx = (x - a) `div` g
- dy = (y - b) `div` g
- g = gcd (abs (x - a)) (abs (y - b))
- pts = [(a + i * dx, b + i * dy) | i <- [1..g-1]]
- in all (not . (arr !)) pts
- numVisible p = length (filter (\q -> q /= p && sight p q) asts)
- print (maximum (map numVisible asts))
+ asts = map fst (filter snd (assocs arr))
+ sight (a,b) (x,y) =
+ let dx = (x - a) `div` g
+ dy = (y - b) `div` g
+ g = gcd (abs (x - a)) (abs (y - b))
+ pts = [(a + i * dx, b + i * dy) | i <- [1..g-1]]
+ in all (not . (arr !)) pts
+ numVisible p = length (filter (\q -> q /= p && sight p q) asts)
+ -- (cent@(centx, centy), centNumVis) = maximumBy (comparing snd) (zip asts (map numVisible asts))
+ (cent@(centx, centy), centNumVis) = ((8, 3), 42)
+
+ print centNumVis
+
+ print cent
+
+ let -- atan2R' dy dx
+ -- | dy <= 0, dx < 0 = abs dy % abs dx : -inf -> 0
+ -- | dy > 0, dx < 0 = abs dy % abs dx : 0 -> inf
+ -- | dy > 0, dx == 0 = 0
+ -- | dy > 0, dx > 0 = abs dy % abs dx : inf -> 0
+ -- | dy <= 0, dx > 0 = abs dy % abs dx : 0 -> -inf
+ -- | dy < 0, dx == 0 = 1
+ -- | otherwise = undefined -- (dx, dy) == (0, 0)
+ threeLine (cx, cy) (a, b) (x, y) = (a - cx) * (y - cy) == (x - cx) * (b - cy)
+ distsq (a, b) (x, y) = (x - a) * (x - a) + (y - b) * (y - b)
+ otherAsts = sortOn (\(x, y) -> atan2 (fromIntegral (centx - x) :: Double) (fromIntegral (y - centy)))
+ (filter (/= cent) asts)
+ groups' = map (sortBy (comparing (distsq cent))) (groupBy (threeLine cent) otherAsts)
+ groups = last groups' : init groups'
+ zapRound l = (map head l, filter (not . null) (map tail l))
+ zapped = concat (takeWhile (not . null) (map fst (tail (iterate (zapRound . snd) (undefined, groups)))))
+
+ mapM_ print groups
+ print zapped
+ print (zapped !! 199)
+
+ -- let (n200x, n200y) = otherAsts !! 199
+ -- print (n200x * 100 + n200y)
--
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