226. Design Hit Counter

Design a hit counter which counts the number of hits received in the past 5 minutes (i.e., the past 300 seconds). Your system should accept a timestamp parameter (in seconds granularity), and you may assume that calls are being made to the system in chronological order (i.e., timestamp is monotonically non-decreasing). Several hits may arrive roughly at the same time. Implement the HitCounter class: - HitCounter() Initializes the object of the hit counter system. - void hit(int timestamp) Records a hit that happened at timestamp (in seconds). - int getHits(int timestamp) Returns the number of hits in the past 5 minutes from timestamp (i.e., the past 300 seconds).