"""

Moving Average from Data Stream

Calculate the moving average of integers in a sliding window of fixed

size using a bounded deque.

Reference: https://leetcode.com/problems/moving-average-from-data-stream/

Complexity:

Time: O(1) per call to next

Space: O(size)

"""

from __future__ import annotations

from collections import deque

class MovingAverage:

"""Computes the moving average over a sliding window.

Examples:

>>> m = MovingAverage(3)

>>> m.next(1)

1.0

>>> m.next(10)

5.5

"""

def __init__(self, size: int) -> None:

"""Initialize the moving average calculator.

Args:

size: The window size for the moving average.

"""

self.queue: deque[int] = deque(maxlen=size)

def next(self, val: int) -> float:

"""Add a value and return the current moving average.

Args:

val: The next integer in the data stream.

Returns:

The current moving average as a float.

"""

self.queue.append(val)

return sum(self.queue) / len(self.queue)