feat: add solution for design twitter in python

Author: bujosa

alternative/medium/design_twitter.py

@@ -0,0 +1,71 @@
+from typing import List
+import heapq
+
+class Twitter:
+
+    def __init__(self):
+        """
+        Initialize your data structure here.
+        """
+        self.tweets = {}
+        self.follows = {}
+        self.time = 0
+        
+    def postTweet(self, userId: int, tweetId: int) -> None:
+        if self.tweets.get(userId) is None:
+            self.tweets[userId] = []
+
+        self.tweets[userId].append([self.time, tweetId])
+        self.time -= 1
+        
+
+    def getNewsFeed(self, userId: int) -> List[int]:
+        minHeap = []
+        res = []
+
+        if self.follows.get(userId) is None:
+            self.follows[userId] = set()
+
+        self.follows[userId].add(userId)
+
+        for followeeId in self.follows[userId]:
+            if followeeId in self.tweets:
+                index = len(self.tweets[followeeId]) - 1
+                count, tweetId = self.tweets[followeeId][index]
+                minHeap.append([count, tweetId, followeeId, index - 1])
+        
+        heapq.heapify(minHeap)
+
+        while len(res) < 10 and minHeap:
+            count, tweetId, followeeId, index = heapq.heappop(minHeap)
+            res.append(tweetId)
+            if index >= 0:
+                count, tweetId, self.tweets[followeeId][index]
+                heapq.heappush(minHeap, [count, tweetId, followeeId, index - 1])
+
+        return res
+        
+
+    def follow(self, followerId: int, followeeId: int) -> None:
+        if self.follows.get(followerId) is None:
+            self.follows[followerId] = set()
+
+        self.follows[followerId].add(followeeId)
+        
+
+    def unfollow(self, followerId: int, followeeId: int) -> None:
+        if followeeId in self.follows[followerId]:
+            self.follows[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)
+
+twitter = Twitter()
+twitter.postTweet(1, 5)
+assert twitter.getNewsFeed(1) == [5]