A Novel Discrete Global-Best Harmony Search Algorithm for Solving 0-1 Knapsack Problems

Algorithm 1

The procedure of improvising a new harmony.

(1) for   𝑗=1 to 𝐷  do

(2)  //memory consideration

(3)  if   rand(0,1)⩽HMCR  then

(4)   Choose a harmony 𝑥_𝑖 from HM randomly, 𝑖∈[1..HMS]

(5)   𝑥^′_𝑗=𝑥_𝑖,𝑗 // a new harmony 𝑥^′=(𝑥^′₁,…,𝑥^′_𝐷)

    // pitch adjustment

(6)   if   rand(0,1)⩽PAR  then

(7)    𝑥^′_𝑗=𝑥^′_𝑗±rand(0,1)⋅𝑏𝑤 // 𝑏𝑤 is a constant to be predetermined

(8)   end if

(9)   else

(10)   𝑥^′_𝑗=𝐿_𝑗+rand(0,1)⋅(𝑈_𝑗−𝐿_𝑗) // random selection

(11)  end if

(12) end for