Track Highest-Earning Experience

You are building a core component for a real-time analytics system that tracks the profitability of experiences on a large online platform.

Implement a function that processes a sequence of operations and returns the result of each query.

You are given three arrays of equal length:

• operations[i]: either 'U' for an update or 'Q' for a query
• experiences[i]: the name of the experience involved in operation i
• deltas[i]: the profit change for the experience if operations[i] == 'U'; otherwise this value is ignored

Rules:

• For an update operation 'U', add deltas[i] to the current total earnings of experiences[i]
• For a query operation 'Q', return the name of the experience with the highest total earnings at that moment
• If an experience has not been updated before, treat its earnings as 0 before applying its first update
• If multiple experiences are tied for the highest earnings, returning any one of them is acceptable
• You may assume each query happens after at least one update

Return an array containing the answers for all query operations, in order.

Example:

• operations = ['U', 'U', 'Q', 'U', 'Q']
• experiences = ['GameA', 'GameB', '', 'GameA', '']
• deltas = [5, 7, 0, 4, 0]

Processing:

• Update GameA by +5 → totals: GameA = 5
• Update GameB by +7 → totals: GameB = 7
• Query → return GameB
• Update GameA by +4 → totals: GameA = 9
• Query → return GameA

Output: ['GameB', 'GameA']

Design an efficient solution for processing many updates and queries.

Track Highest-Earning Experience

You are building a real-time analytics component for an online platform. Given a sequence of update and query operations, return the answer for each query.

You are given three arrays of equal length:

• operations[i]: either 'U' for an update or 'Q' for a query
• experiences[i]: the experience name involved in operation i
• deltas[i]: the profit change if operations[i] == 'U'; otherwise it is ignored

Processing rules:

• For an update 'U', add deltas[i] to the current total earnings of experiences[i]
• For a query 'Q', return the name of the experience with the highest total earnings at that moment
• If an experience is updated for the first time, its previous total is 0
• If multiple experiences are tied for the highest earnings, any one of them is acceptable
• Queries only consider experiences that have been updated at least once so far
• You may assume every query happens after at least one update

Return a list containing the answers to all query operations in order.

Constraints

• 1 <= len(operations) == len(experiences) == len(deltas) <= 200000
• operations[i] is either 'U' or 'Q'
• For update operations, experiences[i] is a non-empty string
• -10^9 <= deltas[i] <= 10^9
• Each query occurs after at least one update

Hints

1. Use a hash map to store the current total earnings for each experience.
2. A single max variable is not enough if an update can decrease an experience's total. Consider a max-heap with lazy removal of outdated totals.