Sliding Window Temperature Monitor

You are building a sensor data aggregator that continuously records temperature readings from multiple sensors. Each reading comes with a timestamp (an integer representing seconds since epoch) and a temperature value (a float). The readings are guaranteed to arrive in chronological order (i.e., non-decreasing timestamps).

Your task is to design and implement a class (or a set of functions) that supports the following two operations:

1. record(timestamp, temperature): Record a new temperature reading with the given timestamp.

2. get_average(timestamp): Return the average temperature of all readings in the time window [timestamp - 300, timestamp], where 300 seconds (5 minutes) is the fixed sliding window duration. If there are no readings in this window, return 0 (or an appropriate value indicating no data).

Requirements:

• Both operations should be optimized to handle a large number of readings efficiently.
• You should focus on making the get_average query run fast, even if that means using additional space.
• Consider edge cases where multiple readings have the same timestamp or when there are no readings in the specified window.

Implement your solution in the programming language of your choice.