model:
sets:
city/1..51/:u;
link(city,city):d,x;
endsets
data:
d=@file('C:\Users\MI\Desktop\sd_que3.txt');
@text()= @writefor(link(i,j)|x(i,j)#GT#0:' x(',i,',',j,')=',x(i,j));
enddata
min=@sum(link:d*x);
@for(city(j):@sum(city(i)|j#ne#i:x(i,j))=1);
@for(city(i):@sum(city(j)|j#ne#i:x(i,j))=1);
@for(link(i,j)|i#NE#j#and#i#gt#1:u(i)-u(j)+51*x(i,j)<=50);
@for(link:@bin(x));
end