2023-09-17 13:08:12 +0000 UTC

class Twitter:

    def __init__(self):
        self.tweets = []
        self.following = defaultdict(set)

    def postTweet(self, userId: int, tweetId: int) -> None:
        self.tweets.append((userId, tweetId))

    def getNewsFeed(self, userId: int) -> List[int]:
        tweets, following = [], self.following[userId]
        for poster, tweet in reversed(self.tweets):
            if poster != userId and poster not in following:
                continue
            tweets.append(tweet)
            if len(tweets) == 10:
                break
            
        return tweets

    def follow(self, followerId: int, followeeId: int) -> None:
        self.following[followerId].add(followeeId)

    def unfollow(self, followerId: int, followeeId: int) -> None:
        self.following[followerId].discard(followeeId)

# Your Twitter object will be instantiated and called as such:
# obj = Twitter()
# obj.postTweet(userId,tweetId)
# param_2 = obj.getNewsFeed(userId)
# obj.follow(followerId,followeeId)
# obj.unfollow(followerId,followeeId)