Re: [eclipse-clp-users] Minimizing a parameter that depends on global state

From: Sergey Dymchenko <kit1980_at_gmail.com>
Date: Fri, 7 Oct 2011 00:16:17 +0300
On Thu, Oct 6, 2011 at 5:31 PM, Thorsten Winterer
<thorsten_winterer_at_web.de> wrote:
> Here is a test case that Sergey supplied where proving optimality was too
> expensive for CLP:
>
> solve(9, [](1, 2, 1, 4, 5, 6, 7, 4, 3, 1, 2, 3, 4, 5, 6, 7, 8, 9,
>             9, 8, 7, 6, 5, 4, 3, 2, 1, 9, 8, 7, 6, 5, 4, 3, 2, 1,
>             9, 8, 3, 2, 1, 9, 8, 7, 6, 5, 4, 3, 2, 1, 9, 8, 3, 2,
>             1, 9, 8, 7, 6, 5, 4, 3, 2, 1, 9, 8, 3, 2, 1, 9, 8, 7,
>             6, 5, 4, 3, 2, 1, 9, 8, 1, 1, 2, 3, 4, 5, 6, 7, 8, 9,
>             1, 1, 2, 3, 4, 5, 6, 7, 8, 9), S).
>
> Assuming that the strategy is optimal and using search/6 alone, it can be
> solved in 0.01 seconds. Proving optimality takes forever with the CLP
> program, though  (I stopped it eventually). Your eplex program takes 0.5
> seconds with CPLEX to find a (proven) optimal solution.

Unfortunately, with OSI solvers it takes forever...

Sergey.
Received on Thu Oct 06 2011 - 21:16:23 CEST

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