[fval,route]=sa_tsp(d,10,0.1,.87)
n=length(d);%the number of cities
L=100*n;%the length of Markov chain
route=randperm(n);%the initial traveling route
fval=value(route,d);%the initial goal value
t=t0;
tic
while t>tf
for i=1:L
[fval_after,route_after]=exchange(route,d);
if fval_after<fval
route=route_after;
fval=fval_after;
elseif exp((fval-fval_after)/t)>rand
route=route_after;
fval=fval_after;
else route=route;
fval=fval;
end
end
t=alpha*t;
end
toc
function fval=value(route,d)%used for reckoning the goal value of the selected traveling route
n=length(d);
fval=0;
for i=1:n-1
fval=fval+d(route(i),route(i+1));
end
function [fval_after,route_after]=exchange(route,d)
n=length(d);
location1=ceil(n*rand);
location2=ceil(n*rand);%the location of two exchanged number
loc1=min(location1,location2);loc2=max(location1,location2);
middle_route=fliplr(route(loc1:loc2));%the part route which has been exchanged
route_after=[route(1:loc1-1) middle_route route(loc2+1:n)];%the after traveling route
fval_after=value(route_after,d);