/** Follower follows a followee. If the operation is invalid, it should be a no-op. */
public void Follow(int followerId, int followeeId)
{
var user = Users.Find(x => x.ID == followerId);
if (user != null)
{
user.FollowerIDs.Add(followeeId);
}
else
{
var newUser = new TweetUser(followerId);
newUser.FollowerIDs.Add(followeeId);
Users.Add(newUser);
}
}
/** Compose a new tweet. */
public void PostTweet(int userId, int tweetId)
{
TweetOrders.Add(tweetId);
var user = Users.Find(x => x.ID == userId);
if (user != null)
{
TweetNews.Add(tweetId, user);
}
else
{
var newUser = new TweetUser(userId);
Users.Add(newUser);
TweetNews.Add(tweetId, newUser);
}
}