Find path from departure to destination

Good day I just got a question which is the following

you have an vector like this

[JFK, LXA, SNA, RKJ, LXA, SNA]

each 2 group define a route. so,

JFK -> LXA
SNA -> RKJ
LXA -> SNA

Find the path from departure to destination. note: departure and destination are not known.

The final destination should be

JFK-> LXA -> SNA -> RKJ

The function signature is something like this

vector<string> findPath(vector<string> airports)
{

}