Hit Counter

Implement HitCounter(capacity), where capacity >= 1 is the window length in seconds. hit(timestamp) records one hit and returns None. count(timestamp) returns hits in (timestamp-capacity, timestamp], excluding the left boundary. ALL method timestamps are nonnegative integers and nondecreasing across calls, including count calls; duplicate timestamps are separate hits. Use supplied fake times only, never a real clock. Discard expired hits to bound retained history. Examples (JSON; null means Python None): Input: {"capacity": 3, "operations": [["hit", [0]], ["hit", [1]], ["count", [2]], ["count", [3]]]} Output: [null, null, 2, 1] Input: {"capacity": 5, "operations": [["hit", [1]], ["hit", [1]], ["hit", [1]], ["count", [1]], ["count", [6]]]} Output: [null, null, null, 3, 0]

class HitCounter:

    def __init__(self, capacity: int):
        """Implement this operation according to the statement."""
        pass

    def hit(self, timestamp: int) -> None:
        """Implement this operation according to the statement."""
        pass

    def count(self, timestamp: int) -> int:
        """Implement this operation according to the statement."""
        pass