troubles adding a constraint with a count of bool variables about good_lp

[Crypto-Spartan]

I'm not sure exactly how the MIP solver library was implemented, I just imported and used it within my python code. I would assume it was written in C or C++, but I never actually looked into it.

However, the rust code runs substantially faster than the python code ran. The fastest iteration of the python code was around 4-5 seconds, the rust code runs in about 0.3-0.5 seconds.

Thanks for the library, and thanks for your help!

[lovasoa]

Hello and thanks for getting in touch !

The first syntax you mentioned should work already

model = model.with(constraint!(team2_bools.iter().sum() == 5))

You may just need to help rust a little by adding a type annotation

model = model.with(constraint!(team2_bools.iter().sum::<Expression>() == 5))

or to make things clearer

let team1_score : Expression = team1_bools.iter().sum(); 
model = model.with(constraint!(team1_score == 5))

[lovasoa]

As an aside, what do you mean exactly by

I just really want to use rust for the increased speed.

?

Whether you define your model in python or in rust, the optimizer itself is a compiled library (written in C++ most of the time). So rewriting your code from python to rust will increase speed only if your model is tiny, or if startup time is important.