What is this girl's deal? How do I resist?

Dude she likes you plain and simple. She's showing you that in a very immature way but suspect she is immature. Do yourself a favor...don't talk to her and definitely don't respond to anything she says or does. To her that's encouragement. You see her coming you turn the other way. You own her NO EXPLANATIONS! You are you're own man and its time you start acting like one. Confronting her will only make the situation worse.