import Data.Vector as V
import Data.Set as Set

main :: IO ()
main = putStr $ show $ insertZeroes (Set.fromList [1,3, 5]) (V.fromList [1..10])

insertZeroes :: Set Int -> Vector Int -> Vector Int
insertZeroes v xs = V.foldMap f $ indexed xs
  where
    f :: (Int, Int) -> Vector Int
    f (idx, x)
      | Set.member idx v = V.fromList [0, x]
      | otherwise = V.singleton x