A Hybrid Soft Computing Approach for Subset Problems

Algorithm 4

Hybrid ACO + CP for SCP and SPP.

(1) Begin

(2) InitParameters()

(3) While remain iterations do

(4)  Foreach ant do

(5)   While solution is not completed and (𝑇𝑎𝑏𝑢𝐿𝑖𝑠𝑡 <> 𝑗) do

(6)    Choose next column 𝑗 with Transition Rule Probability

(7)    feasible(𝑖):= AC3𝑋∉𝑆^𝑘,𝐷_𝑋∉𝑆^𝑘,𝐶_𝐼𝑗{/* Filtering 𝑖∈𝐼_𝑗*/}

(8)    If feasible(𝑖) ∀𝑖 then

(9)     AddColumnToSolution(𝑗)

(10)    Else

(11)     Backtracking(𝑗){/* Set 𝑗 uninstantiated */}

(12)    End If-Else

(13)    AddColumnToTabuList(𝑗)

(14)   End While

(15)  End Foreach

(16)  UpdateOptimum()

(17)  UpdatePheromone()

(18) End While

(19) Return 𝐵𝑒𝑠𝑡𝑆𝑜𝑙𝑢𝑡𝑖𝑜𝑛

(20) End