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Train Schedule Optimisation Challenge

Optimizing train schedules


Reference Value Instance 5

Posted by Palstek almost 2 years ago

Can you tell us what the best (i.e. lowest) penalty is, that you were able to compute for instance 5 to give us a reference frame? Also: Do I understand it correctly, that for all the other instances 0-penalty-solutions are possible? Thanks for the info


Posted by jordiju  almost 2 years ago |  Quote

Thing is, if one knows the objective value for the best solution, this information can be used to reduce the search space and (possible greatly) speed up the algorithm.

But in real life you don’t know in advance if there exists a feasible schedule, or how much penalty the best penalty will have. So I would actually prefer to stay tight-lipped about what the best penalties are.

If you are asking because you are wondering if your solutions will really be accepted, what I can say is that you may trust the validator. I know, I know, every once in a while we have a problem with it, such as it not recognizing violated connections, but it should be all good now and if you do not receive any ERRORS, then yes, your solution is valid.

Does this answer alleviate your concerns?

Posted by LeoB  almost 2 years ago |  Quote

I guess I can give you a small hint: As the instance descriptions tell you, the problem instance 4 and 5 are very similar. With some tools you might find out what the difference is. This I guess, will also give you an upper bound of the problem.