Streaming Tagged Window Sum | Dataford Interview Questions

Given a stream of tagged values, implement an API of the form sum(String tag, int windowSize) that returns the sum of the values for a given tag within the given window size.

Asked in the Coding II stage. Treat the window independently for each tag: it contains the most recent windowSize values added with that tag, ignoring values belonging to other tags.

Contract

Implement process_operations(operations). Each operation is a list: ['add', tag, value] or ['sum', tag, windowSize]. Return a list containing the result of every sum operation, in order.

Constraints

1 <= len(operations) <= 10^5
Each operation is either ['add', tag, value] or ['sum', tag, windowSize]
Tags are non-empty strings
Values are integers in the range -10^9 to 10^9
1 <= windowSize <= 10^5

Function Signature

def process_operations(operations):

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