Define a class called StringSet that will be used to store a set of STL

strings. Use an array or a vector to store the strings. Create a constructor

that takes as an input parameter an array of strings for the initial values

in the set. Then write member functions to add a string to the set,

remove a string from the set, clear the entire set, return the number of

strings in the set, and output all strings in the set. Overload the + operator so that it returns the union of two StringSet objects. Also overload the * operator so that it returns the intersection of two StringSet

objects. Write a program to test all member functions and overloaded

operators in your class.