Determine Reachability in Train Schedule

You are given a train schedule represented as a list of train routes. Each route is a list of station names, where the element at index `t` is the station that train visits at absolute time `t`. Every train starts operating at time `0` and stops after its last listed station. A passenger starts at station `start` at time `0`. The passenger may: - board any train that is at their current station at the current time, - stay on that train to any later station on the same route, - get off at any visited station, - wait at a station for any amount of time, - transfer to another train that arrives at that station at a later time. Write a function `can_reach(schedule, start, destination)` that returns whether the passenger can eventually reach `destination`. Assumptions: - `start` and `destination` both appear somewhere in the schedule. - Station names are strings. Example: `schedule = [["A", "B", "C"], ["D", "B", "E"]]` Expected results: - `can_reach(schedule, "A", "C") -> true` - `can_reach(schedule, "A", "E") -> true` - `can_reach(schedule, "C", "A") -> false` - `can_reach(schedule, "A", "D") -> false` Important edge case: `schedule = [["A", "B", "C", "D", "E"], ["O", "B", "G", "H", "Z"]]` `can_reach(schedule, "A", "Z") -> true` Explanation: the passenger can ride the first train from `A` to `B`, get off at time `1`, wait at `B`, then board the second train when it arrives at `B` and continue to `Z`.