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.
- Each test case will have at most
- Each test case will call
pingwith strictly increasing values of
- Each call to ping will have
1 <= t <= 10^9.
调用 ping 的时候会给定时间，求过去的 3000 ms 内 ping 的次数，可以用队列来记录 ping。