Function SetupIncrFlowCosts 

pub unsafe extern "C" fn SetupIncrFlowCosts(
    costs: *mut *mut c_void,
    incrcosts: *mut *mut incrcostT,
    flows: *mut *mut c_short,
    nflow: c_long,
    nrow: c_long,
    narcrow: c_long,
    narcsperrow: *mut c_int,
    params: *mut paramT,
) -> c_int

Calculates the costs for positive and negative dflow flow increment if there is zero flow on the arc.