Create design_hit_counter.py

LC 362

Author: ananya-research

data_structures/queues/design_hit_counter.py

@@ -0,0 +1,39 @@
+from collections import deque
+
+
+class HitCounter:
+    """
+    A counter that records hits (events) and can return
+    the number of hits in the past 5 minutes (300 seconds).
+
+    >>> hc = HitCounter()
+    >>> hc.hit(1)
+    >>> hc.hit(2)
+    >>> hc.hit(300)
+    >>> hc.get_hits(300)
+    3
+    >>> hc.get_hits(301)
+    2
+    """
+
+    def __init__(self) -> None:
+        self.hits: deque[int] = deque()
+
+    def hit(self, timestamp: int) -> None:
+        """Record a hit at the given timestamp (in seconds)."""
+        self.hits.append(timestamp)
+
+    def get_hits(self, timestamp: int) -> int:
+        """
+        Return the number of hits in the past 5 minutes
+        from the given timestamp.
+        """
+        while self.hits and self.hits[0] <= timestamp - 300:
+            self.hits.popleft()
+        return len(self.hits)
+
+
+if __name__ == "__main__":
+    import doctest
+
+    doctest.testmod()