grb 1.3.0

use grb::*;

mod workforce;

fn main() {
    let mut env = Env::new("workforce3.log").unwrap();
    env.set(param::LogToConsole, 0).unwrap();

    let mut model = workforce::make_model(&env).unwrap();
    model.optimize().unwrap();

    match model.status().unwrap() {
        Status::Infeasible => {
            let mut model = model.try_clone().unwrap();
            model
                .set_attr(attr::ModelName, "assignment_relaxed".to_owned())
                .unwrap();

            // do relaxation.
            let constrs = model.get_constrs().unwrap().to_vec();
            let slacks = {
                let (_, svars, _, _) = model
                    .feas_relax(
                        RelaxType::Linear,
                        false,
                        std::iter::empty(),
                        std::iter::empty(),
                        constrs.iter().map(|&c| (c, 1.0)),
                    )
                    .unwrap();
                svars
            };
            model.optimize().unwrap();

            println!("slack variables: ");
            for slack in slacks {
                let value = model.get_obj_attr(attr::X, &slack).unwrap();
                let vname = model.get_obj_attr(attr::VarName, &slack).unwrap();
                if value > 1e-6 {
                    println!("  * {} = {}", vname, value);
                }
            }
        }

        Status::Optimal => {
            println!("The model is feasible and optimized.");
        }

        Status::InfOrUnbd | Status::Unbounded => {
            println!("The model is unbounded.");
        }

        status => {
            println!("Optimization is stopped with status {:?}", status);
        }
    }
}