Model Elevator Dispatch for Sequential and Overlapping Calls

Design the state model and dispatch logic for an elevator simulation that returns the elevator assigned to the final call in a sequence. Explain two versions: calls that finish before the next call begins, and calls that may overlap in time. ### Part 1 — Sequential Calls There are `n` elevators, all initially on floor 1. Each call finishes before the next arrives. Explain what each call must specify, how a dispatch policy chooses an elevator, and how the chosen elevator's state changes after completion. #### What This Part Should Cover Preserve the initial floor and sequential completion assumption. Identify missing pickup, destination, eligibility, and tie-breaking rules rather than silently supplying them. ### Part 2 — Overlapping Calls Elevators now start in arbitrary supplied states and may still be serving an earlier call when a new one arrives. Explain how to advance their states to the new call's time before deciding which elevator can serve it. #### What This Part Should Cover Represent time, position, direction, availability, and pending work as needed by the declared movement and dispatch policy. Define how equal-time events are ordered and how to identify the elevator assigned to the final call. ### Constraints The movement speed, door time, capacity, dispatch objective, and call format are unspecified. Initial states in the overlapping version are inputs, not a requirement to generate random states. Any concrete policy used in an example must be labeled hypothetical. This exercise asks for a conditional design, not a unique executable answer. ### Clarifying Questions - Does a call include a pickup floor, destination, direction, and timestamp? - Must an elevator be idle to accept a call, or can it add compatible stops? - Do we choose nearest distance, earliest pickup time, or another objective? - What happens when no elevator can immediately accept a call? ```hint Advance time before dispatch The elevator that was closest at the previous call may have moved or become available by the next call's timestamp. ``` ### What a Strong Answer Covers - Correct sequential and overlapping state models with explicit unresolved policies. - A consistent event-processing order and distinction between assignment and completion. - Conditional algorithms, complexity, and boundary cases tied to the selected rules. ### Follow-up Questions - How would equal pickup times be resolved deterministically? - How would accepting intermediate stops change the state representation?