A Hybrid Demon Algorithm for the Two-Dimensional Orthogonal Strip Packing Problem

Algorithm 1

Hybrid demon algorithm.

HDA()

(1)  LS();

(2)  give an initial value and ;

(3)   while  the stop criterion is not yet satisfied  do

(4)   for    to    do

(5)     randomly select two pieces and in ;

(6)     swap the order of pieces and ;

(7)     ← HeuristicPacking();

(8)     ;

(9)     if    then

(10)      ;

(11)      if    then

(12)       ;

(13)       ;

(14)      else

(15)       swap the order of pieces and ;

(16) randomly flip a coin;

(17)  if  coin comes up heads  then

(18)  sort all the pieces by non-increasing ordering of perimeter size to obtain ;

(19)  else

(20)  sort all the pieces by non-increasing ordering of width size and obtain ;

(21)  return  ;