Algorithm 4 Parallel strategy for bi-directional ring topology

1:for  $g=1:4$  do 2:    Use $g+1$ to find the remainder of 4 and record the remainder as $sg$ 3:    Use $g-1$ to find the remainder of 4 and record the remainder as $vg$ 4:    if $sg==0$ then 5:        $sg=4$ 6:    end if 7:    if $vg==0$ then 8:        $vg=4$ 9:    end if 10:    Calculate the average position of the optimal particle in group $sg$ and group $vg$ and its fitness value 11:    if The fitness value of the average position < The fitness value of the optimal particle in group g then 12:        Replace the position of the optimal particle in group g and its fitness value using the average position and its fitness value 13:    end if 14:end for