Different Transfer Functions for Binary Particle Swarm Optimization with a New Encoding Scheme for Discounted {0-1} Knapsack Problem

Algorithm 2

Repair operator.

	Input: Solution , value vector , weight vector , index vector , and knapsack capacity .
	Output: Solution
(1)	% Repair phase
(2)	n  length (x)/2 for i = 1 : do
(3)	k  floor ((id (i) − 1)/3);
(4)	r  mod (id (i) − 1, 3);
(5)	ifthen
(6)
(7)
(8)	else ifthen
(9)	x (2k + 1)  0
(10)	x (2k + 2)  0
(11)	ifthen
(12)
(13)
(14)	else ifthen
(15)	x (2k + 1)  0
(16)	x (2k + 2)  0
(17)	ifthen
(18)
(19)
(20)	else ifthen
(21)	x (2k + 1)  0
(22)	x (2k + 2)  0
(23)	% Optimization phase
(24)	fordo
(25)	k  floor ((id (i) − 1)/3);
(26)	r  mod (id (i) − 1, 3);
(27)	ifthen
(28)
(29)
(30)	ifthen
(31)	x (2k + 1)  0; x (2k + 2)  1
(32)	ifthen
(33)	x (2k + 1)  1; x (2k + 2)  0
(34)	ifthen
(35)	x (2k + 1)  1; x (2k + 2)  1
(36)	return