n个城市选m个供应点,要考虑到每个城市建立供应点的费用和城时之间的距离,并求出供给点所供给的城市怎么用lingo怎么求,model:sets:city/1..49/:cost,need;station/1..8/:;road(city,city):u,dis;bj(station,

Question

n个城市选m个供应点,要考虑到每个城市建立供应点的费用和城时之间的距离,并求出供给点所供给的城市怎么
用lingo怎么求,model:
sets:
city/1..49/:cost,need;
station/1..8/:;
road(city,city):u,dis;
bj(station,city):x;
endsets
n=@size(city);
data:
cost=@ole('d:\book1.xls','y');!从excel中读入每个城市建立供应点所花费的费用
need=@ole('d:\book2.xls','x')；!
每个城市所需货物数量
dis=@ole('d:\lingodata.xls','dist');!两个城市之间的距离
enddata
@for(city(i):@sum(station(k):x(k,i))=1);!每个城市只能被供给一次
min=(a+b);
@for(station(k):
@sum(bj(k,i):(x(k,i)*cost(i)))

Answer 1

sets:
city/1..49/:cost,need;
station/1..8/:;
road(city,city):u,dis;
bj(station,city):x;
endsets
n=@size(city);
data:
cost=@ole('d:\book1.xls','y');!从excel中读入每个城市建立供应点所花费的费用;
need=@ole('d:\book2.xls','x');!每个城市所需货物数量;
dis=@ole('d:\lingodata.xls','dist');!两个城市之间的距离;
enddata
@for(city(i):@sum(station(k):x(k,i))=1);!每个城市只能被供给一次;
min=(a+b);
@for(station(k):
@sum(bj(k,i):(x(k,i)*cost(i)))