Description
Question :
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., the timestamp
is monotonically increasing). 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 attimestamp
(in seconds). Several hits may happen at the sametimestamp
.int getHits(int timestamp)
Returns the number ofhits
in the past 5 minutes fromtimestamp
(i.e., the past 300 seconds).
Example 1:
Input
["HitCounter", "hit", "hit", "hit", "getHits", "hit", "getHits", "getHits"]
[[], [1], [2], [3], [4], [300], [300], [301]]
Output
[null, null, null, null, 3, null, 4, 3]
Explanation :
HitCounter hitCounter = new HitCounter();
hitCounter.hit(1); // hit at timestamp 1.
hitCounter.hit(2); // hit at timestamp 2.
hitCounter.hit(3); // hit at timestamp 3.
hitCounter.getHits(4); // get hits at timestamp 4, return 3.
hitCounter.hit(300); // hit at timestamp 300.
hitCounter.getHits(300); // get hits at timestamp 300, return 4.
hitCounter.getHits(301); // get hits at timestamp 301, return 3.