Moderate -0.5 This is a standard dynamic programming tabulation question requiring backward pass from destination to find latest departure time. While it involves multiple steps and careful bookkeeping of times, it's a routine application of the tabular method taught in D2 with no conceptual challenges—students follow the algorithmic procedure mechanically. Slightly easier than average due to being purely procedural.
3 Throughout this question all clock times are in Greenwich Mean Time (GMT).
An aeroplane needs to arrive at its destination at 3pm. The places it can pass through on its route are shown in the network, together with the flying times, in hours, between them.
\includegraphics[max width=\textwidth, alt={}, center]{661c776a-9c9f-485f-b0fd-f58651e3e065-4_609_1523_486_255}
Use a dynamic programming tabulation, working backwards from 3pm at the destination, to find the latest time that the aeroplane could set off. If the aeroplane takes off at its latest time, which places does it pass through, and at what time does it reach each of these places?
3 Throughout this question all clock times are in Greenwich Mean Time (GMT).\\
An aeroplane needs to arrive at its destination at 3pm. The places it can pass through on its route are shown in the network, together with the flying times, in hours, between them.\\
\includegraphics[max width=\textwidth, alt={}, center]{661c776a-9c9f-485f-b0fd-f58651e3e065-4_609_1523_486_255}
Use a dynamic programming tabulation, working backwards from 3pm at the destination, to find the latest time that the aeroplane could set off. If the aeroplane takes off at its latest time, which places does it pass through, and at what time does it reach each of these places?
\hfill \mbox{\textit{OCR D2 2012 Q3 [9]}}