i have a User class with the private users to personalize the profile of the user eg name,age,favourites. i would like to compare the favourites of two given users and output the common favourites. since i'll be using a vector for this, My question is how do i group the users to vector (user1,user2) so i can compare the favourites of any given member and output the result. this is what i have so far

user.cpp
--------

```
 using namespace std;

 vector<string> user;

 int  adduser();
 int adduser()
 {

   ofstream thefile;  
   thefile.open("users.txt", ios::app);

   string firstname;
   string lastname;
   int age;
   string favourites;

   cout<<"Enter your  Name: ";
   cin>>name;
   thefile << name << ' ';

   cout<<"Enter your age: ";

   cin>>age;
   thefile << age << ",";

   cout<<"Enter your favourites: ";

   cin>>favourites;
   thefile << favourites<< ",";

   thefile.close();
   cout<<" Completed."<<endl;
   return 0;
 }
 common favourites()
 {

 //how do make it so i have something like user1 and user2 
 //which are both vectors so when i enter the name of 
 //user1 and user2 i can compare thier favourites and output the common ones

 }  

```