Algorithm 3. Pseudocode of the iterated tabu search algorithm.

Iterated_Tabu_Search procedure;

/ 0-level hierarchical iterated tabu search algorithm

/ input: p—current solution

/ output: p〈0〉—the best found solution

/ parameter: Q〈0〉—number of iterations of the ITS algorithm

begin

p〈0〉: = p;

for q〈0〉 := 1 to Q〈0〉 do begin

apply Tabu_Search to p and get p•;

if z(p•) < z(p〈0〉) then p〈0〉: = p•; / the best found solution is memorized

if q〈0〉 < Q〈0〉 then begin

p: = Candidate_Acceptance(p•, p〈0〉);

apply mutation procedure to p

endif

endfor

end.