Dynamic Reduction-Expansion Operator to Improve Performance of Genetic Algorithms for the Traveling Salesman Problem

Pseudocode 1

Pseudo-code of the clustering and coding processes.

= % All nodes

= ⌀ % Set of coded nodes

= -coordinate of node i

= -coordinate of node i

= 1 % index for coded nodes

for = 1:N

for = + 1:

if

coded_nodes(r,1) = % node i is stored for clustering

coded_nodes(r,2) = % node j is stored for clustering

coded_nodes(r,3) = % x-coordinate of equivalent coded node for (i,j)

coded_nodes(r,4) = % y-coordinate of equivalent coded node for (i,j)

U = U% U is updated (i and j are removed from U)

R = % R is updated (equivalent coded node added to R)

r = r + 1

end

end

end

% Now, U contains the remaining nodes i that were not clustered or coded. These are added

to R as follows:

for= 1:

coded_nodes(r,1) = % node i is stored for assignment of new index r

coded_nodes(r,2) = - % there is no node j for non-clustered nodes

coded_nodes(r,3) = % -coodinate of node

coded_nodes(r,4) = % -coodinate of node

r = r + 1

end