Leetcode学习笔记：933. Number of Recent Calls

Write a class RecentCounter to count recent requests.

It has only one method: ping(int t), where t represents some time in milliseconds.

Return the number of pings that have been made from 3000 milliseconds ago until now.

Any ping with time in [t - 3000, t] will count, including the current ping.

It is guaranteed that every call to ping uses a strictly larger value of t than before.

实现：

    Queue<Integer> q;

    public RecentCounter() {
        q = new LinkedList<>();
    }
    
    public int ping(int t) {
        q.offer(t);
        while (q.peek() < t - 3000) { q.poll(); }
        return q.size();
    }