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Leetcode 3433. Count Mentions Per User

Simulate the time-ordered events while maintaining each user's online/offline status (OFFLINE makes a user offline for 60 units, and status changes at a timestamp apply before MESSAGEs at that timestamp) and parse MESSAGE tokens—id# (may repeat), ALL (everyone), and HERE (currently online users)—to accumulate per-user mention counts.

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Leetcode 3433. Count Mentions Per User | Hello Interview