Degree-Constrained -Minimum Spanning Tree Problem

Algorithm 5

Classical ACO algorithm for the DC MST problem.

	Data: an instance of the DCMST problem using degree .
	Result: a feasible solution and its objective function value.
	Step 1
	Initialize parameters , , , and the set of ants ()
	, , ,
	,
	Step 2
	While () do
	,
	ForEachdo
	Construction of each ant tour
	Randomly assign an initial position for the ant according to graph and construct a tour using all remaining nodes of .
	Find best solution
	Compute the length of
	Denote by the length of consecutive nodes in starting from node
	Compute
	If () then
	Set and save the best tour of length in
	, ,
	Update accumulated pheromone matrix
	ForEachdo
	,
	Update pheromone matrix
	ForEachdo
	Return best feasible solution found and its objective function value