Was Zeus the father of Perseus and Hercules?

Yes, he was.

Perseus was son of Zeus and Danae and his quest was to bring the head of Gorgon Medusa back to Polydectes King of Seriphos.

On his way back he met Andromeda and made her his wife.

The head of the Gorgon was given to goddes Athena as present for her assistance and she embeded it at her shield/ aegis for protection.

Descendants of Perseus were the royal houses of Mykynae, Sparta, Persia and the most famous of all Herakles/ Hercules.

After their death Perseus and Andromeda were honored by the gods by setting the galaxies of Perseus and Adromeda