lingo程序（一道建模题） [推广有奖]

model:
title 年费用最少;
sets:
section/1..5/;
district/1..3/;
link2(section,section):d;
link3(district,district):c;
link4(section,district):x,b;
link1(section,district,section,district):y;
endsets
data:
b=0 10 10
  0 15 20
  0 10 15
  0 20 15
  0 5  15;
d=0    0    1000 1500 0
  0    0    1400 1200 0
  1000 1400 0    0    2000
  1500 1200 0    0    700
  0    0    2000 700  0;
c=100 130 90
  130 50  140
  90  140 50;
enddata
max=10000*@sum(link4(i,j):x(i,j)*b(i,j))-@sum(link1(i,j,k,l):d(i,k)*c(j,l)*y(i,j,k,l));
@for(section(i):@sum(district(j):x(i,j))=1);
@for(district(j):@sum(section(i):x(i,j))<=3);
@for(link1(i,j,k,l)|i#lt#k:y(i,j,k,l)-x(i,j)<=0);
@for(link1(i,j,k,l)|i#lt#k:y(i,j,k,l)-x(k,l)<=0);
@for(link1(i,j,k,l)|i#lt#k:x(i,j)+x(k,l)-y(i,j,k,l)<=1);
@for(link4:@gin(x));
@for(link1:@gin(y));
end