2. (20%) Consider designing an APP for Instagram(IG). The APP consists of users, friends, photos and videos. Write a C++ program to maintain the entities for the IG APP in the following way. (a) Choose an appropriate data structure and design a Users class to maintain the user info and friendship structure. Each user has an ID, a name, and a list of other users who are friends. (b) Write an AddFriend function to add a friend to the friend list. (C) Write an AddPost function to add a post, possibility with a photo or a video. (d) Write DeletPost and DeleteFriend functions to delete a post and a friend link. Deleting a post implies the deletion of all photos or videos associated with that post. Test your functions properly in the main program