// f *= g
inline void
fac_mul(fac_t f, fac_t g)
{
fac_t tmp;
fac_resize(fmul, f[0].num_facs + g[0].num_facs);
fac_mul2(fmul, f, g);
tmp[0] = f[0];
f[0] = fmul[0];
fmul[0] = tmp[0];
}
/* f /= gcd(f,g), g /= gcd(f,g) */
void
fac_remove_gcd(mpz_t p, fac_t fp, mpz_t g, fac_t fg)
{
long int i, j, k, c;
fac_resize(fmul, min(fp->num_facs, fg->num_facs));
for (i=j=k=0; i<fp->num_facs && j<fg->num_facs; ) {
if (fp->fac[i] == fg->fac[j]) {
c = min(fp->pow[i], fg->pow[j]);
fp->pow[i] -= c;
fg->pow[j] -= c;
fmul->fac[k] = fp->fac[i];
fmul->pow[k] = c;
i++; j++; k++;
} else if (fp->fac[i] < fg->fac[j]) {
i++;
} else {
j++;
}
}
fmul->num_facs = k;
assert(k <= fmul->max_facs);
if (fmul->num_facs) {
bs_mul(gcd, 0, fmul->num_facs);
#if HAVE_DIVEXACT_PREINV
mpz_invert_mod_2exp (mgcd, gcd);
mpz_divexact_pre (p, p, gcd, mgcd);
mpz_divexact_pre (g, g, gcd, mgcd);
#else
#define SIZ(x) x->_mp_size
mpz_divexact(p, p, gcd);
mpz_divexact(g, g, gcd);
#endif
fac_compact(fp);
fac_compact(fg);
}
}
