Single-Commodity Vehicle Routing Problem with Pickup and Delivery Service

Algorithm 1

(IMSA) algorithm.

1. lnitialize(nCounts_max, nChanges_max, 𝑇_start, 𝑇_end, 𝐵,𝐿,𝛼)

2. 𝑥=lnitialSolution( );

3. while (Feasible(x) == FALSE )

4.    𝑥=InitialSoiution( );

5. minDist = Dist(x);

6. for (nCounts = nCounts_max; nCounts > 0; nCounts ⋅⋅)

7.   for (nChanges = nChanges_max; nChanges > 0; nChanges ⋅⋅)

8.      for ( 𝑘=0,𝑇=𝑇_start; (𝑘<𝐵) && (𝑇>𝑇_end)); k ++, 𝑇=𝑇/𝛼)

9.       for (𝑧=0; 𝑧<𝐿; z ++)

10.         𝑦=RandomNeighborSequence(x, nChanges);

11.         if (Feasible(y)== TRUE)

12.          Δ= minDist − Dist(y);

13.          if (𝑝=exp(Δ/𝑇)) > 1.0)

14.            𝑝=1.0;

15.          if (RandomNumber([0,1]) <= p)

16.            if (Δ>0)

17.             𝑥=𝑦;

18.             minDist = Dist(x);