933. Number of Recent Calls
in Coding Interview on Design, Queue
특정 시간 프레임 내의 최근 요청 수를 계산하는 RecentCounter 클래스 구현
class RecentCounter {
LinkedList<Integer> slideWindow;
// 최근 통화 수
public RecentCounter() {
this.slideWindow = new LinkedList<Integer>();
}
// T: O(1)
public int ping(int t) {
// step 1). append the current call
slideWindow.addLast(t);
// step 2). invalidate the outdated pings
while (slideWindow.getFirst() < t - 3000) {
slideWindow.removeFirst();
}
return slideWindow.size();
}
}
/**
* Your RecentCounter object will be instantiated and called as such:
* RecentCounter obj = new RecentCounter();
* int param_1 = obj.ping(t);
*/
