lpx_integer/lpx_simplex question? Re: [Help-glpk] lpx_integer problem "optiomal solution of LPrelaxation"

[Joonas Timo Taavetti Kekoni]

>You need to run lpx_simplex first.
>I believe it says that in the documentation for lpx_integer;

Yes, of course. It said that quite directly.

        I did not find it as I was looking for flag:
        (LPX_SOLVE_RELAXTION or something like that).

Another question.

If I need to solve same data with different objective funtion, do
I need to run also lpx_simplex again or just only lpx_integer?

If I change column coefficients then I need to run lpx_simplex again?

Is it enough to just do lpx_set_class(... LPX_LP ) after doing
lpx_integer , but before  doing
lpx_simplex, or do I need to do something else?