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  1. Prepare
  2. Functional Programming
  3. Ad Hoc
  4. Subset Sum
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Subset Sum

  • mykhail0
     + 0 comments

    Simple O(n lg n) solution in Haskell using Data.Set:

    import Control.Monad (replicateM_)
import Data.Int
import Data.Set hiding (foldl)
import Data.List (sort)

main :: IO ()
main = getLine >> do
  l' <- getLine
  let l = preprocess $ fmap read $ words l'
  readLn >>= flip replicateM_
    (readLn >>= print . maybe (- 1) (flip findIndex l) . flip lookupGE l)

preprocess :: [Int64] -> Set Int64
preprocess = fromList . scanl (+) 0 . reverse . sort