/*
Copyright (C) 2020 Daniel Schultz
This file is part of FLINT.
FLINT is free software: you can redistribute it and/or modify it under
the terms of the GNU Lesser General Public License (LGPL) as published
by the Free Software Foundation; either version 3 of the License, or
(at your option) any later version. See <https://www.gnu.org/licenses/>.
*/
#include "fmpz.h"
#include "fmpz_mod.h"
int fmpz_mod_is_invertible(const fmpz_t a, const fmpz_mod_ctx_t ctx)
{
int res;
fmpz_t d;
fmpz_init(d);
fmpz_gcd(d, a, ctx->n);
res = fmpz_is_one(d);
fmpz_clear(d);
return res;
}