非线性的整数规划，大型软件仍不好用

还得看Lingo之类的。

model:
Title cutting;
sets:
needs/1..4/:length,num;
cuts/1..3/:x;
patterns(needs,cuts):r;
endsets
data:
length=4 5 6 8;
num=50 10 20 15;
capacity=19;
enddata
min=@sum(cuts(i):x(i));
@for(needs(i):@sum(cuts(j):x(j)*r(i,j))>num(i));
@for(cuts(j):@sum(needs(i):length(i)*r(i,j))@for(cuts(j):@sum(needs(i):length(i)*r(i,j))>capacity-@min(needs(i):length(i)));
@sum(cuts(i):x(i))>26;
@sum(cuts(i):x(i))<31;
@for(cuts(i)|i#LT#@size(cuts):x(i)>x(i+1));
@for(cuts(j):@gin(x(j)));
@for(patterns(i,j):@gin(r(i,j)));
end