How to get multiple solution

Hi Yang Du,

Curious. Could you try to add an artificial objective that you minimize (for maximization, the logic of negative/positive would have to be inverted), just as an experiment? Maybe there is only a single optimum?

Anyhow, an alternative approach and a slightly more involved variant would be to implement a preintsol callback (unlike intsol, this is called BEFORE the solution will be accepted by the Optimizer) and always reject the solution via the p_reject field, see https://www.fico.com/fico-xpress-optimization/docs/latest/solver/optimizer/HTML/XPRSaddcbpreintsol.html (and do whatever you want to do with the solution, like storing it away yourself. Note that due to heuristics, the Optimizer might now try to present you the same solution multiple times, so it would be up to you to check this (e.g., by a pairwise comparison). That workflow is independent of the MIPADDCUTOFF approach.

Timo