How can you say that As You Like It is a drama of victory of good over evil?

In As You like It, the theme of good vs evil is portrayed in man's dual nature, and his ability to simultaneously contain both of these elements.

The characters Frederick and Oliver both do evil things......... Frederick usurps his brother's throne and then banishes Rosalind from court because she's in love with Orlando. Oliver (Orlando's brother) treats his brother horribly, persecuting him to the point that he too is forced to flee into the forest.

In the end, Orlando saves Oliver from certain death (at the paws of a lioness), leading Oliver to repent for his mistreatment. Frederick also repents and restores his brother to the throne. So the good and evil here lies inside of the characters; they behave badly and then they repent. No one is killed, there is no tragedy, in fact............ at the end, everyone marries (and they do it as a group).

I will try to come up with a few more specifics for you......... but this is actually a pretty lighthearted play.