ampl - 在 GLPK 中对 1 <= i < j < k <= n 求和

Question

我一直在尝试通过使用 GNU 来解决序列化问题。但我无法写出像下面这样的总结。

param n, integer, >= 3;
set O := 1..n;
param d{i in O,j in O};
var x{i in O,j in O}, binary, i < j;
var v{i in O,j in O,k in O}, binary, i < j < k;
maximize total: sum{i in O,j in O, i<j}(d[i,j] - d[j,i])* x[i,j] + sum{i in O,j in O, i<j}d[j,i];
s.t. tran{i in O,j in O,k in O, i<j<k}: x[i,j] + x[j,i] - x[i,k] + v[i,j,k] = 1;

谢谢

Answer 1

您应该在“这样的”子句中使用:而不是：,i < j

sum{i in O,j in O: i < j} ...
#                ^ note ':' here