Multispecies Coevolution Particle Swarm Optimization Based on Previous Search History

Algorithm 1

Pseudocode of fitness tree construction.

   Input: Fitness tree and A new solution

   Output: Fitness tree

   %% A new solution z is inserting into the fitness tree

()  Initialization: Current node is the root node Curr_node = root, RF = 0

()  If (Curr_node has two child nodes x and y)

()     Define the comparing dimension j:

()         

()     If

()        ;

()     Else

()        ;

()     End If and Goto Step  ()

()  Else

()     Insert a “virtual” child node to Curr_node, create a “real” child node that records z “under” the

         virtual child node.

()  End If