upd

algorithms/labs/lab8/code/hash/3.py

@@ -0,0 +1,50 @@
+import heapq
+
+
+class Twitter:
+    def __init__(self):
+        self.time = 0
+        self.tweets = {}
+        self.follows = {}
+
+    def postTweet(self, userId, tweetId):
+        self.time += 1
+        if userId not in self.tweets:
+            self.tweets[userId] = []
+        self.tweets[userId].append((-self.time, tweetId))
+
+    def getNewsFeed(self, userId):
+        heap = []
+        if userId in self.tweets:
+            heap.extend(self.tweets[userId][-10:])
+        if userId in self.follows:
+            for v in self.follows[userId]:
+                if v in self.tweets:
+                    heap.extend(self.tweets[v][-10:])
+        heapq.heapify(heap)
+        res = []
+        while heap and len(res) < 10:
+            res.append(heapq.heappop(heap)[1])
+        return res
+
+    def follow(self, followerId, followeeId):
+        if followerId == followeeId:
+            return
+        if followerId not in self.follows:
+            self.follows[followerId] = set()
+        self.follows[followerId].add(followeeId)
+
+    def unfollow(self, followerId, followeeId):
+        if followerId in self.follows and followeeId in self.follows[followerId]:
+            self.follows[followerId].remove(followeeId)
+
+
+if __name__ == "__main__":
+    tw = Twitter()
+    tw.postTweet(1, 5)
+    print(tw.getNewsFeed(1))
+    tw.follow(1, 2)
+    tw.postTweet(2, 6)
+    print(tw.getNewsFeed(1))
+    tw.unfollow(1, 2)
+    print(tw.getNewsFeed(1))