Design Twitter
Detailed guide and Python implementation for the 'Design Twitter' problem.
Problem Statement
Design a simplified version of Twitter where users can post tweets, follow/unfollow another user, and is able to see the 10 most recent tweets in the user's news feed.
Implement the Twitter class:
- Twitter() Initializes your twitter object.
- postTweet(userId: int, tweetId: int) Composes a new tweet with ID tweetId by the user userId.
- getNewsFeed(userId: int) -> List[int] Retrieves the 10 most recent tweet IDs in the user's news feed.
- follow(followerId: int, followeeId: int) The user with ID followerId started following the user with ID followeeId.
- unfollow(followerId: int, followeeId: int) The user with ID followerId started unfollowing the user with ID followeeId.
Input is a list of operations and arguments. Implement a function twitter(operations: list, arguments: list) -> list that returns a list of results (None for constructor/postTweet/follow/unfollow, and List[int] for getNewsFeed).
- •1 <= userId, followerId, followeeId <= 500
- •0 <= tweetId <= 10^4
- •All the tweets have unique IDs
- •At most 30000 calls will be made in total
Examples
operations = ["Twitter", "postTweet", "getNewsFeed", "follow", "postTweet", "getNewsFeed", "unfollow", "getNewsFeed"], arguments = [[], [1, 5], [1], [1, 2], [2, 6], [1], [1, 2], [1]]
[None, None, [5], None, None, [6, 5], None, [5]]
User 1 posts tweet 5. News feed: [5]. User 1 follows 2. User 2 posts tweet 6. News feed: [6, 5]. User 1 unfollows 2. News feed: [5].
Need a Hint?
Edge Cases to Watch
- Empty input structures
- Single element inputs
- Large numerical bounds
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