static void
_mpq_harmonic_odd_balanced(fmpz_t num, fmpz_t den, long n)
{
mpz_t p, q;
mp_ptr t, v;
mp_size_t ts, vs;
long size;
if (n <= 0)
{
fmpz_zero(num);
fmpz_one(den);
return;
}
/* TODO: we could avoid the copying/allocation overhead when there
is guaranteed to be sufficient space in res already */
size = FLINT_BIT_COUNT(n) * (n+2) + 2*FLINT_BITS;
mpz_init2(p, size);
mpz_init2(q, size);
t = p->_mp_d;
v = q->_mp_d;
mpn_harmonic_odd_balanced(t, &ts, v, &vs, 1, n+1, n, 1);
p->_mp_size = ts;
q->_mp_size = vs;
fmpz_set_mpz(num, p);
fmpz_set_mpz(den, q);
mpz_clear(p);
mpz_clear(q);
_fmpq_canonicalise(num, den);
}
void
_fmpq_randtest(fmpz_t num, fmpz_t den, flint_rand_t state, mp_bitcnt_t bits)
{
ulong x = n_randlimb(state);
fmpz_randtest(num, state, bits);
fmpz_randtest_not_zero(den, state, bits);
switch (x % 16)
{
case 0:
fmpz_set_si(num, 1);
break;
case 1:
fmpz_set_si(num, -1);
break;
case 2:
fmpz_set_si(num, 2);
break;
case 3:
fmpz_set_si(num, -2);
break;
}
switch ((x / 16) % 16)
{
case 0:
fmpz_set_si(den, 1);
break;
case 2:
fmpz_set_si(den, 2);
break;
}
_fmpq_canonicalise(num, den);
}
void nf_elem_add_si(nf_elem_t a, const nf_elem_t b, slong c, const nf_t nf)
{
if (nf->flag & NF_LINEAR)
{
fmpz * den = LNF_ELEM_DENREF(a);
fmpz * num = LNF_ELEM_NUMREF(a);
nf_elem_set(a, b, nf);
if (c >= 0)
fmpz_addmul_ui(num, den, c);
else
fmpz_submul_ui(num, den, -c);
_fmpq_canonicalise(num, den);
}
else if (nf->flag & NF_QUADRATIC)
{
fmpz * den = QNF_ELEM_DENREF(a);
fmpz * num = QNF_ELEM_NUMREF(a);
slong len = 2;
nf_elem_set(a, b, nf);
while (len != 0 && fmpz_is_zero(num + len - 1))
len--;
if (c >= 0)
fmpz_addmul_ui(num, den, c);
else
fmpz_submul_ui(num, den, -c);
_fmpq_poly_canonicalise(num, den, len);
} else
{
fmpq_poly_add_si(NF_ELEM(a), NF_ELEM(b), c);
}
}
void _fmpq_poly_resultant(fmpz_t rnum, fmpz_t rden,
const fmpz *poly1, const fmpz_t den1, long len1,
const fmpz *poly2, const fmpz_t den2, long len2)
{
if (len2 == 1)
{
if (len1 == 1)
{
fmpz_one(rnum);
fmpz_one(rden);
}
else if (len1 == 2)
{
fmpz_set(rnum, poly2);
fmpz_set(rden, den2);
}
else
{
fmpz_pow_ui(rnum, poly2, len1 - 1);
if (fmpz_is_one(den2))
{
fmpz_one(rden);
}
else
{
fmpz_pow_ui(rden, den2, len1 - 1);
}
}
}
else /* len1 >= len2 >= 2 */
{
fmpz_t c1, c2;
fmpz *prim1, *prim2, *g;
long lenG = len2;
fmpz_init(c1);
fmpz_init(c2);
_fmpz_vec_content(c1, poly1, len1);
_fmpz_vec_content(c2, poly2, len2);
prim1 = _fmpz_vec_init(len1);
prim2 = _fmpz_vec_init(len2);
g = _fmpz_vec_init(len2);
_fmpz_vec_scalar_divexact_fmpz(prim1, poly1, len1, c1);
_fmpz_vec_scalar_divexact_fmpz(prim2, poly2, len2, c2);
_fmpz_poly_gcd(g, prim1, len1, prim2, len2);
FMPZ_VEC_NORM(g, lenG);
if (lenG > 1)
{
fmpz_zero(rnum);
fmpz_one(rden);
}
else /* prim1, prim2 are coprime */
{
fmpz_t t;
fmpz_init(t);
_fmpz_poly_resultant(rnum, prim1, len1, prim2, len2);
if (!fmpz_is_one(c1))
{
fmpz_pow_ui(t, c1, len2 - 1);
fmpz_mul(rnum, rnum, t);
}
if (!fmpz_is_one(c2))
{
fmpz_pow_ui(t, c2, len1 - 1);
fmpz_mul(rnum, rnum, t);
}
if (fmpz_is_one(den1))
{
if (fmpz_is_one(den2))
fmpz_one(rden);
else
fmpz_pow_ui(rden, den2, len1 - 1);
}
else
{
if (fmpz_is_one(den2))
fmpz_pow_ui(rden, den1, len2 - 1);
else
{
fmpz_pow_ui(rden, den1, len2 - 1);
fmpz_pow_ui(t, den2, len1 - 1);
fmpz_mul(rden, rden, t);
}
}
_fmpq_canonicalise(rnum, rden);
fmpz_clear(t);
}
fmpz_clear(c1);
fmpz_clear(c2);
_fmpz_vec_clear(prim1, len1);
_fmpz_vec_clear(prim2, len2);
_fmpz_vec_clear(g, len2);
}
}
