Design Timestamp Counter

"""
Design a  hit counter which counts the number of hits received in the past 5 minutes.

Each function accepts a timestamp parameter (in seconds granularity) and you may assume that calls are being made to the system in chronological order (ie, the timestamp is monotonically increasing). You may assume that the earliest timestamp starts at 1.

It is possible that several hits arrive roughly at the same time.


"""

from collections import Counter

class HitCounter:
    def __init__(self):
        """
        Initialize the HitCounter with a Counter to keep track of timestamp occurrences.
        """
        self.hits = Counter()

    def hit(self, timestamp: int) -> None:
        """
        Record a hit at a given timestamp.
        Each hit increments the count for the specific timestamp.

        :param timestamp: The current timestamp (in seconds granularity).
        """
        self.hits[timestamp] += 1

    def get_hits(self, timestamp: int) -> int:
        """
        Retrieve the number of hits in the past 5 minutes (300 seconds) from the current timestamp.

        :param timestamp: The timestamp at which to get the number of hits.
        :return: Total number of hits in the last 5 minutes.
        """
        # Filter out the timestamps that are older than 5 minutes and sum their hit counts.
        return sum(count for time, count in self.hits.items() if time > timestamp - 300)

# Example usage:
# hit_counter = HitCounter()
# hit_counter.hit(timestamp)
# total_hits = hit_counter.get_hits(timestamp)