Roblox OA 面试真题解析：Sliding-Window Rate Limiter 滑动窗口限流

Given chronologically sorted requests, each with a timestamp, user ID, and experience, implement a sliding-window rate limiter.

A request is allowed only if both its user and experience have fewer than maxInWindow previously allowed requests within the current windowLength; otherwise, it is rejected.

Return a boolean array indicating whether each request is allowed.

这道题考察的是滑动窗口限流的设计：请求按时间顺序到达，需要同时维护“用户维度”和“experience 维度”两套最近窗口内的通过记录。每次处理新请求时，只要这两个维度中任意一个在当前窗口内的已放行请求数达到 <code>maxInWindow</code>，就拒绝该请求；否则允许，并把它计入对应窗口。实现时通常用哈希表配合队列 / 双端队列清理过期请求，核心是正确判断窗口边界并高效更新计数，整体适合在线处理场景。