[gecode-users] Starting search from a solution

[Luca Di Gaspero]

Hi all,

I am currently facing this issue: for modeling a sort of VRP problem I have the need to find a solution and then perturb the problem to add a new decision variable (say a new customer to be visited). I would like to let the search engine explore the search space of the modified problem starting from the solution of the original problem, is there a way to implement this behavior?

I make a concrete example, suppose the nodes to be visited are initially {1, 2, 3}, the decision variables is the set succ of successors (succ[i] \in {1..3}, i = 1, …, 3) and the first solution satisfying also the other constraints is succ = [3, 1, 2].
Now I need to add a node 4, so the successors becomes succ[i] \in {1..4}, i =1, …, 4 and I would like to start the exploration of the tree close to the solution succ = [3, 1, 2, _] (actually it should be [3, 1, 2, 4] because of distinctness). 

Thanks in advance for your answer.

All the best,

Luca