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module Codevs1080 where | |
import qualified Data.Vector as V; -- Use Vector for O(1) indexing | |
data Cmd = Add Int Int Int -- Order Index Addition | |
| Inq Int Int Int -- Order Left-Index Right-Index | |
deriving Show | |
logSolve :: [Int] -> [Cmd] -> [Int] | |
logSolve srcs cmds = V.toList addSum | |
where | |
srcVec = V.fromList srcs | |
cmdVec = V.fromList cmds | |
inqVec = V.filter (\a -> case a of Inq _ _ _ -> True | |
_ -> False) cmdVec | |
addVec = V.filter (\a -> case a of Add _ _ _ -> True | |
_ -> False) cmdVec | |
rawSum = V.map (\rg@(Inq _ l r) -> (rg, V.sum (V.slice l (r - l + 1) srcVec))) inqVec | |
addSum = V.map (\((Inq inqOrd l r), s) -> s + (V.sum (V.map (\(Add _ i x) -> x) (V.filter (\(Add addOrd i x) -> l <= i && i <= (r - l + 1) && addOrd < inqOrd) addVec)))) rawSum -- F**k, this time mutable programs possess better performance | |
testSrc :: [Int] | |
testSrc = [4, 5, 6, 2, 1, 3] | |
testCmd :: [Cmd] | |
testCmd = [(Add 0 2 5), (Inq 1 0 3), (Add 2 0 9), (Inq 3 1 5)] | |
test = logSolve testSrc testCmd |
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