please use c++

here is the question: "I've been trying to track all the unique Pokemon I've seen in my travels (I'm thinking of calling it a Pokedex). And, I've been wanting to try out the accumulate function from the numeric library.I've put all the names of the Pokemon I've seen (in order) in a vector (of string's), but I need a custom function (named 'unique_pokemon') that will only accumulate the pokemon the first time I've seen them. Please write that function so I can use it in my tests."

1 t include