/*Purges the user from the friends list of all users in the targets list.*/
void unAddfriend(User *exiledFriend, const User *user) {
    if (!exiledFriend) {
        return;
    }

    int difference, iterator = 0;
    for (iterator = 0; iterator < MAX_FRIENDS && 
    exiledFriend->friends[iterator]; iterator++) {
        if (exiledFriend->friends[iterator] == user) {
            difference++;
        }

        if (iterator + difference < MAX_FRIENDS) {
            exiledFriend->friends[iterator] = 
            exiledFriend->friends[iterator + difference];
        } else {
            exiledFriend->friends[iterator] = NULL;
        }
    }

    unAddfriend(exiledFriend->next, user);
}