import java.util.*;

public class hitCounter {

/*

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.

* */

/*

HitCounter counter = new HitCounter();

// hit at timestamp 1.

counter.hit(1);

// hit at timestamp 2.

counter.hit(2);

// hit at timestamp 3.

counter.hit(3);

// get hits at timestamp 4, should return 3.

counter.getHits(4);

// hit at timestamp 300.

counter.hit(300);

// get hits at timestamp 300, should return 4.

counter.getHits(300);

// get hits at timestamp 301, should return 3.

counter.getHits(301);

* */

// method 1: 首先是最简单的用一个queue的方法

// 每hit一下，就add 一个timestamp

// 每次gethits时，就一直remove 直到peek在300范围内，返回queue的size就是当前范围内有多少hits

Queue<Integer> q;

public hitCounter() {

q = new LinkedList<>();

}

public void hit(int timestamp){

q.add(timestamp);

}

public int getHits(int timestamp){

while(!q.isEmpty() && q.peek() <= timestamp - 300){

q.remove();

}

return q.size();

}

}