Mobile Chat Event Ordering

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Your question is Mobile Chat Event Ordering. Start with the requirements on the right.

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Problem

Given a list of chat events for a mobile messaging system, reconstruct the visible conversation state. Each event is one of: send, deliver, read, edit, or delete, and includes a message_id, timestamp, and optional fields such as text or user_id. Events may arrive out of order and may be duplicated. Return the final ordered list of non-deleted messages with their latest text and highest status (sent < delivered < read).

Constraints

1 <= len(events) <= 2 * 10^5
Each event is [event_type, message_id, timestamp, payload]
event_type is one of send, deliver, read, edit, delete
0 <= timestamp <= 10^9
Duplicate events may appear and events may arrive in any order

Function Signature

def reconstruct_chat(events):

Your solutionPython 3

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