Research Article

Degree-Constrained -Minimum Spanning Tree Problem

Algorithm 3

VNS algorithm for the DCMST problem using classical random local search strategy.
Data: an instance of the DCMST problem using degree .
Result: a feasible solution and its objective function value.
If () then
 Execute Algorithm 2 using parameters
 Save feasible solution found and its objective function value
Else
Classical random local search strategy:
 Generate an initial random tuple of vertices. Let denote this set of vertices and its complement,
 Execute Algorithm 2 using parameters
 Save the initial feasible solution found and its objective function value
  ,
  , ,
While () do
   
  For to do
   Interchange randomly an element of with an element of
   , execute Algorithm 2 using parameters
  If (a better solution is obtained) then
   Save the new solution and set ,
    , , , ,
  Else
    , ,
  If () then
    
   If () then
     
   Else
     
Return best feasible solution obtained and its objective function value