Re: [Rails-devel] Route calculation validations

[John A. T. <ja...@ja...>]

On Tue, Apr 20, 2010 at 1:32 AM, alexti <al...@sh...> wrote:

> Considering that both trains are identical, how the order in which they
> are iterated over would matter? Assuming we're talking about brute force
> algorithm I believe that you're thinking about something else (not the
> effects of the train iteration order). But let me elaborate on my
> reasoning.
>

I am just saying if you choose the best route for one train first, and then
find the best route for remaining trains, you won't find the optimal run for
all the trains.


> However, your comment brings an interesting point: let's say we still have
> the same example, but now we have 3 trains: one 3 and two 2s.
> Longest-to-shortest order will result in 3 and 2 being used and
> shortest-to-longest in 2 and 2 being used. And in both cases alternative
> option (2+2 instead of 3+2 and vica versa) won't even be attempted. The
> reason for that is that I don't consider 'null' route a route. To have
> complete scan I would need to simply eliminate a train and find the
> optimal solution with the remaining trains. I wonder if this matters in
> any existing 18xx. But, after reading recent design discussion about train
> obsolescence, I realize that this may actually matter if an obsolete train
> has reduced revenue. That means that in the example above running 3+2 on
> the exactly same route set might be better than 2+2.


Similar issues apply in games where only certain types of trains get certain
bonuses (and in fact you might have the two trains left get different
bonuses for different stops).

-- 
John A. Tamplin