int make_friends(const char *name1, const char *name2, User *head) {

    // then get the users from the linked list
    // loop thorugh the linked list until you either get the names of the friends or NULL
    // if at least one user does not exist, return 4
    // just use find user

    // find_user(const char *name, const User *head)
    User *user1 = find_user(name1, head);
    User *user2 = find_user(name2, head);

    // first check if name1 = name2
    // if true, return 3

    if (user1 == user2) {
        return 3;
    }

    // check if user do not exist
    if ((user1 == NULL) || (user2 == NULL)) {
        return 4;
    }

    // check if users are friends
    // return 1 if already friends
    // return 2 if not friends but at least one has max friends

    // loop through the array to determine how many friends there are
    int num_friends_one = 0;
    int num_friends_two = 0;
    for (int i = 0; i < MAX_FRIENDS; i++) {
        if (user1->friends[i] != NULL) {
            num_friends_one += 1;
        }
        if (user2->friends[i] != NULL) {
            num_friends_two += 1;
        }
    }


    int friend_in_array = 1; // this means not in the array
    for (int i = 0; i < num_friends_one; i++) {
        if (user1->friends[i] == user2) {
            friend_in_array = 0;  // this means the friend is in the array
        }
    }

    if (friend_in_array == 0) {  // this means they are already friends
        return 1;
    }
    
    if ((num_friends_one == MAX_FRIENDS) || (num_friends_two == MAX_FRIENDS)) {
        return 2;
    }

    // if you get to here it means everything is good
    // loop through the first user's friends list and add it to the end
    // or can just use strlen() and determine where to add it - this is better

    // add other friend user to second user's friend list
    // return 0;

    user1->friends[num_friends_one - 1] = user2;
    user2->friends[num_friends_two - 1] = user1;

    return 0;
}
Make two users friends with each other.  This is symmetric - a pointer to
 * each user must be stored in the 'friends' array of the other.
 *
 * New friends must be added in the first empty spot in the 'friends' array.
 *
 * Return:
 *   - 0 on success.
 *   - 1 if the two users are already friends.
 *   - 2 if the users are not already friends, but at least one already has
 *     MAX_FRIENDS friends.
 *   - 3 if the same user is passed in twice.
 *   - 4 if at least one user does not exist.