Algorithm 1. Optimal matching calculation by EC

i = 0

Forj = 0: S − 1 Do

//random generation of parameters t, a, b, k, h

initial a population POPi(j) = (t, a, b, k, h)

calculate fitness of each member in POPi(j)

End For

Whilei < Iterations Do

i = i + 1

//sorting and classification

order POPi−1 by fitness in ascending and divide them into 4 levels

//acceleration search

For j = 0:S − 1 Do

If POPi−1(j) is at level kind

//where, kind = 1, 2, 3, 4, indicating the classification level of each population

//random generation of new parameters t, a, b, k, h in the neighborhood

//i.e., a = rand(POPi−1(j).a, kind)

generate new kind+1 subpopulations nPOP from POPi−1(j)

calculate fitness of each member in nPOP

//sorting subpopulations

order nPOP by fitness in ascending

//select best subpopulation nPOP as POPi−1(j + S)

POPi−1(j + S) = nPOP(0)

End If

End For

//global selection

order POPi−1 by fitness in ascending, where there are 2S populations

select the top S from POPi−1 as POPi

End While