Implement Dasher Pay Calculation (Minute-based, Overlapping Orders)

Problem: Implement Dasher Pay Calculation (Minute-based, Overlapping Orders) You need to implement a module/class to calculate a delivery dasher’s pay. The system contains multiple orders; for each order, the dasher earns money per minute from accept to deliver. Pay rules Each order has a per-minute rate. For a given dasher and any minute: If the dasher is simultaneously active on k orders during that minute (i.e., all k orders are “in progress” for that minute), then the income for that minute is: income_this_minute = k * rate Assume all orders for the same dasher share the same rate (if you think per-order rates are needed, state and support it). Time definition Time is represented in integer minutes. Each order provides accept_minute and deliver_minute. The active interval is half-open: [accept_minute, deliver_minute). Example: accept=10, deliver=12 covers minutes 10 and 11 (2 minutes). Input / API Design an OOP-style interface and internal data structures that support: Adding an order with dasher_id, accept_minute, deliver_minute (and optional rate). Querying total earnings for a given dasher_id (or for all dashers). Output Return the total pay for the requested dasher (integer or float depending on rate). Constraints (to be clarified with interviewer) Number of orders N up to 1e5. Time range in minutes up to 1e9. You must explain time/space complexity. Example Let rate = 2: Order1: dasher=A, [0, 3) Order2: dasher=A, [1, 2) Per minute: minute 0: 1 order -> 1*2=2 minute 1: 2 orders -> 2*2=4 minute 2: 1 order -> 1*2=2 Total pay = 8 Requirements Implement the core logic. Provide at least 5 test cases covering edge scenarios (no overlap, full overlap, partial overlaps, 1-minute orders, large time gaps, etc.). Example Input A 2 order 0 3 rate=2 order 1 2 rate=2 query A Output 8