355. Design Twitter

Practice Design Twitter for free on NudgeCode: Medium, Heap pattern. Write it in Python or JavaScript, run the tests in your browser, and ask for a hint when you are stuck.

Design a small social feed.

• postTweet(userId, tweetId) posts a new tweet with a unique id.
• getNewsFeed(userId) returns the ids of the 10 most recent tweets posted by the user or anyone they follow, newest first (fewer than 10 if there are not that many).
• follow(followerId, followeeId) / unfollow(followerId, followeeId) start or stop following. Following yourself or unfollowing someone you do not follow has no effect.

Each test is a list of operations and their arguments; the expected output lists what each call returns (null for the constructor and for calls that return nothing).

Example

["Twitter","postTweet","getNewsFeed","follow","postTweet","getNewsFeed","unfollow","getNewsFeed"]
[[],[1,5],[1],[1,2],[2,6],[1],[1,2],[1]]
->  [null,null,[5],null,null,[6,5],null,[5]]

Constraints

• 1 <= userId, followerId, followeeId <= 500
• 0 <= tweetId <= 10^4, and every tweet id is unique
• Up to 3 * 10^4 calls in total