力扣（LeetCode）第933题 -- 最近的请求次数

草稿：

python3题解：

class RecentCounter:
    def __init__(self):
        self.q = deque()

    def ping(self, t: int) -> int:
        self.q.append(t)
        while len(self.q) > 0 and t - self.q[0] > 3000:
            self.q.popleft()
        return len(self.q)


# Your RecentCounter object will be instantiated and called as such:
# obj = RecentCounter()
# param_1 = obj.ping(t)