The answer to this question is literally on the first page of a google for "snapchat patent stories"

https://www.wired.com/2016/08/instagrams-snapchat-ripoff-bra...

“The idea of featured ‘Stories’ is not new, so any patents would likely be quite specific to implementation details,” says Wagner. “And because the implementation/interfaces are slightly different, copyright doesn’t provide any protection. This is an area where IP laws don’t prevent the copying of another’s features or innovations.”