Sliding Window Rate Limiter

Problem

Implement a function that simulates a per-client rate limiter for an API. Given a maximum number of requests limit, a time window size window_seconds, and a list of requests as (client_id, timestamp) pairs in non-decreasing timestamp order, return a list of booleans where each value indicates whether that request should be allowed. A client may make at most limit requests in any rolling window_seconds interval.

Constraints

• 1 <= limit <= 10^5
• 1 <= window_seconds <= 10^9
• 1 <= len(requests) <= 2 * 10^5
• requests[i] = (client_id, timestamp)
• client_id is a non-empty string
• 0 <= timestamp <= 10^9
• Request timestamps are given in non-decreasing order