Algorithm 2: SPSOA

Input: Objective function f(x), seagull population size N, dimensional space D, maximum number of iterations T, learning factors $c_1$ and $c_2$

1. Sobol sequence initialize population; 2. Set u and v to 1; 3. While t < T 4.     for i = 1 : N 5.      Calculate seagull migration position ${\overrightarrow{D}}_S$ by Equation (5); 6.      Compute $x^{\prime }$,$y^{\prime }$,$z^{\prime }$,$r$ using Equations (6)–(9); 7.      Calculate seagull attack position ${\overrightarrow{P}}_{S1}(t)$ by Equation (10); 8.      Compute w using Equation (16); 9.      Calculate learning location ${\overrightarrow{P}}_l(t)$ by Equation (15); 10.    Update seagull optimal position ${\overrightarrow{P}}_{bS}(t)$; 11.      t = t + 1; 12.    end for 13. end while 14. Output the global optimal solution.