Question 3: use a class [8]

Suppose a class with the following definition has been implemented for us: 
class StringList {
   public:
      StringList();   // creates an (initially empty) list of strings
      ~StringList();  // deallocates the list of strings
      void insert(string s); // inserts a string in the list
      void displaySorted();  // displays the strings in the list
                             //    sorted alphabetically
   
   private: // the internal list representation
      struct strNode {
         string   str;
         strNode *next, *prev;
      }  *front, *back;
};
Write a main routine that accepts command line arguments (i.e. using argc and argv) and uses the StringList class to display the command line arguments in sorted order. Do not write any code other than the main routine. 
Sample solutiona
int main(int argc, char *argv[])
{
   StringList S;
   for (int i = 0; i < argc; i++) {
       S.insert(argv[i]);
   }
   S.displaySorted();
   return 0;
}