Research Article

Facility Location with Tree Topology and Radial Distance Constraints

Algorithm 1

Proposed heuristics.
Data: input matrices and and input graph .
Result: a feasible solution for .
for each do
Step 1:;
 Set , ;
, ;
 Remove all neighbors of from W;
 Find the minimum spanning tree formed with nodes in S using the Kruskal algorithm;
 Assign each user to its nearest facility in S and compute the objective function value of ;
 Save the current solution found if its objective function value is less than the best found so far;
Step 2:;
while ( is not empty) do
  Let be the vertex with minimum degree in ;
  , ;
  Remove all neighbors of from W;
  Find the minimum spanning tree formed with nodes in S using the Kruskal algorithm;
  Assign each user to its nearest facility in S and compute the objective function value of ;
  Save the current solution found if its objective function value is less than the best found so far;
Return the best solution found and its objective function value;