这是我的示例代码，我的问题是，如果obj1小于0，如何将weight1从2更改为100，请帮帮我，谢谢~~
CP cp = new CP();
IIntExpr demand1 = cp.IntExpr();
IIntExpr supply1 = cp.IntExpr();
IIntExpr obj1 = cp.Diff(demand1, supply1);
IIntExpr demand2 = cp.IntExpr();
IIntExpr supply2 = cp.IntExpr();
IIntExpr obj2 = cp.Diff(demand2, supply2);
int weight1 = 2;
int weight2 = 3;
IIntExpr obj = cp.Sum(cp.Prod(obj1, weight1), cp.Prod(obj2, weight2));
cp.Minimize(obj);