An Improved Sparrow Search Algorithm and Its Application in HIFU Sound Field

Algorithm 1

The improved sparrow search algorithm.

	Input:
	: the number of sparrows
	: the total number of iterations
	: the number of producers
	: the number of scouters
	: the safety value
	Output:
	: the optimal solution
	: the global optimal position
(1)	Using (5) and (6) to initialize a population of sparrows;
(2)	whiledo
(3)	Calculating the fitness value of individuals;
(4)	Ranking the fitness values and finding the current best and worst individual;
(5)	fordo
(6)	Using equations (7) and (11) to update the producers’ position;
(7)	end for
(8)	fordo
(9)	Using (2) or (12) to update the scroungers’ position;
(10)	end for
(11)	fordo
(12)	Using equation (3) to update the scouters’ position;
(13)	end for
(14)	fordo
(15)	if the new position is better than the previous position then
(16)	Using the new position to update the previous position;
(17)	end if
(18)	if the new position is better than the optimal position then
(19)	Using the new position to update the optimal position;
(20)	end if
(21)	end for
(22)
(23)	end while
(24)	return,