Thomas Opfer

In the C API, you can use GRBBinvRowi to do that. Still, this is an advanced routine and you have to know exactly what you are doing. (It can contain slack/artificial variables.)

In addition to that, the warning Warning for adding constraints: zero or small (< 1e-13) coefficients, ignored indicates that you might have run into numerical trouble when creating the model.   Ma...

For Gurobi 8.0, it might be -lgurobi80 .

Undefined references mean that you forgot the library in the compiler command. I am not sure which library is missing, but I guess it is libgurobi_c++.a, so try adding -lgurobi_c++ to the end of yo...

As far as I know, you need an academic site license for this. (cf. https://www.gurobi.com/academia/academic-program-and-licenses/ ) From my experience, I would not expect too much from distributed ...

Can you post an .lp or .mps file of your model? One thing seems strange: In your first constraint, you interate t over range(1-w_max, H) and in the second constraint, you iterate t over trans_per(i...

You can obtain the order of the variables in the current basis, see here: https://www.gurobi.com/documentation/9.0/refman/c_getbasishead.html 

Maybe, this is due to numerical trouble. Can you tell us how large M is?

I think you need constraints that state that not more than one presentation may be in the same room at the same time. Otherwise, that would be perfectly ok.

You could play around with the MIPFocus parameter: https://www.gurobi.com/documentation/9.0/refman/mipfocus.html