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Improves interval tree solution 3

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Abhinav Sarkar 2018-12-06 23:04:03 +05:30
parent 534271d1bd
commit 3b10150e08
1 changed files with 16 additions and 13 deletions
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29
3/3.hs
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@ -6,7 +6,7 @@ import Data.Bits (Bits(shift))
import Data.Function (on)
import qualified Data.Set as Set
import qualified Data.Tree as T
import Data.List (maximumBy, foldl', sort)
import Data.List (maximumBy, foldl', sort, sortOn)
import Data.Ord (comparing)
import Text.Parsec hiding (Empty)
@ -80,6 +80,7 @@ instance Show a => Show (Interval a) where
data IntervalTree a b = Node { itLeft :: IntervalTree a b
, itCenter :: a
, itIntervals :: [(Interval a, b)]
, itEndSortedIntervals:: [Interval a]
, itRight :: IntervalTree a b
}
| Empty a a deriving (Show, Eq)
@ -91,14 +92,14 @@ leftOf (Interval (_, end)) x = end <= x
insert :: (Ord a, Ord b, Bits a, Num a) => (Interval a, b) -> IntervalTree a b -> IntervalTree a b
insert o@(interval, _) tree = case tree of
Empty start end -> go start end (start + half (end - start))
Node l center is r | interval `leftOf` center -> Node (insert o l) center is r
Node l center is r | interval `rightOf` center -> Node l center is (insert o r)
Node l center is r -> Node l center (sort (o:is)) r
Node l center is es r | interval `leftOf` center -> Node (insert o l) center is es r
Node l center is es r | interval `rightOf` center -> Node l center is es (insert o r)
Node l center is es r -> Node l center (sort (o:is)) (sortOn (negate . snd . unInterval) (interval:es)) r
where
go start end center
| interval `leftOf` center = Node (insert o (Empty start center)) center [] (Empty center end)
| interval `rightOf` center = Node (Empty start center) center [] (insert o (Empty center end))
| otherwise = Node (Empty start center) center [o] (Empty center end)
| interval `leftOf` center = Node (insert o (Empty start center)) center [] [] (Empty center end)
| interval `rightOf` center = Node (Empty start center) center [] [] (insert o (Empty center end))
| otherwise = Node (Empty start center) center [o] [interval] (Empty center end)
half = flip shift (-1)
@ -108,13 +109,15 @@ overlappingIntervals f interval = go []
where
go acc t = case t of
Empty _ _ -> acc
Node l _ is _ | not (null is) && interval `leftOf` leftmostStart is -> go acc l
Node l center is _ | interval `leftOf` center -> go (acc' is acc) l
Node _ center is r | interval `rightOf` center -> go (acc' is acc) r
Node l _ is r -> go (go (acc' is acc) l) r
Node l _ is _ _ | not (null is) && interval `leftOf` leftmostStart is -> go acc l
Node _ _ _ es r | not (null es) && interval `rightOf` rightmostEnd es -> go acc r
Node l center is _ _ | interval `leftOf` center -> go (acc' is acc) l
Node _ center is _ r | interval `rightOf` center -> go (acc' is acc) r
Node l _ is _ r -> go (go (acc' is acc) l) r
where
acc' is acc = filter (\(i,_) -> i `f` interval) is ++ acc
leftmostStart = fst . unInterval . fst . head
rightmostEnd = snd . unInterval . head
includingIntervals :: Ord a => Interval a -> IntervalTree a b -> [(Interval a, b)]
includingIntervals =
@ -141,7 +144,7 @@ rectIntervalTrees rects =
toTree :: (Show a, Show b) => IntervalTree a b -> T.Tree String
toTree (Empty start end) = T.Node (show ("E", start, end)) []
toTree (Node l c is r) = T.Node (show ("N", c, is)) [toTree l, toTree r]
toTree (Node l c is _ r) = T.Node (show ("N", c, is)) [toTree l, toTree r]
intervalTreeSolve :: [Rect] -> (Int, [Rect])
intervalTreeSolve rects =
@ -167,6 +170,6 @@ intervalTreeSolve rects =
main :: IO ()
main = do
rects <- readInput . lines <$> getContents
let (overlapArea, noOverlapRects) = bruteForceSolve rects
let (overlapArea, noOverlapRects) = intervalTreeSolve rects
putStrLn $ "Overlap Area = " ++ show overlapArea
putStrLn $ "No overlap rects = " ++ show noOverlapRects