leetcode

commit d32710e7fef4c3ef02351ab80d78a0c48b3822cf
parent 952f59b70f923cbe80b9adae8ae727b46aeb3569
Author: Andrew Laack <andrew@laack.co>
Date:   Wed,  9 Jul 2025 14:47:07 -0500

Completed design twitter

Diffstat:
A
design-twitter/design-twitterV1.py
 | 
89
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

1 file changed, 89 insertions(+), 0 deletions(-)
diff --git a/design-twitter/design-twitterV1.py b/design-twitter/design-twitterV1.py
@@ -0,0 +1,89 @@
+# This approach uses a simple list based approach with sorting.
+# while there is a nice heap + hashmap based approach, given the limited
+# number of insturctions, this approach works quite well given the low
+# asymptotic coefficients.
+
+
+class Tweet:
+    def __init__(self, time, tweetId):
+        self.time = time
+        self.tweetId = tweetId
+
+    def __lt__(self, other):
+        return self.time < other.time
+
+
+class Twitter:
+
+    def __init__(self):
+        self.tweets = {}
+        self.following = {}
+        self.current_time = 0
+
+    def _add_tweet(self, tweetId, userId):
+        tweet = Tweet(self.current_time, tweetId)
+        self.current_time += 1
+        self.tweets[userId].add(tweet)
+
+    def postTweet(self, userId: int, tweetId: int) -> None:
+
+        tweets = self.tweets
+        following = self.following
+
+        if userId in tweets:
+            self._add_tweet(tweetId, userId)
+
+        else:
+            tweets[userId] = set()
+            self._add_tweet(tweetId, userId)
+
+    def getNewsFeed(self, userId: int) -> List[int]:
+
+        tweets = self.tweets
+        following = self.following
+
+        tweet_ls = []
+
+        # or current user posts...
+        if userId in following:
+            ls = list(following[userId])
+            for id in ls:
+                if id in tweets:
+                    tweet_ls.extend(tweets[id])
+
+        if userId in tweets:
+            tweet_ls.extend(tweets[userId])
+
+        tweet_ls.sort(reverse=True)
+
+        if len(tweet_ls) > 0:
+            return [tweet.tweetId for tweet in tweet_ls[0:10]]
+
+        return []
+
+    def follow(self, followerId: int, followeeId: int) -> None:
+
+        tweets = self.tweets
+        following = self.following
+
+        if followerId in following:
+            following[followerId].add(followeeId)
+        else:
+            following[followerId] = set()
+            following[followerId].add(followeeId)
+
+    def unfollow(self, followerId: int, followeeId: int) -> None:
+
+        tweets = self.tweets
+        following = self.following
+
+        if followerId in following:
+            following[followerId].remove(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)