leetcode 933. Number of Recent Calls

class RecentCounter {
    Queue<Integer> q;
    public RecentCounter() {
        q = new LinkedList<Integer>();
    }
    
    public int ping(int t) {
        int threshold = t - 3000;
        while (q.size() != 0 && q.peek() < threshold) {
            q.poll();
        }
        q.add(t);
        return q.size();
    }
}

/**
 * Your RecentCounter object will be instantiated and called as such:
 * RecentCounter obj = new RecentCounter();
 * int param_1 = obj.ping(t);
 */