void fmpz_poly_q_canonicalise(fmpz_poly_q_t rop)
{
fmpz_poly_t gcd;
if (fmpz_poly_is_zero(rop->den))
{
flint_printf("Exception (fmpz_poly_q_canonicalise). Denominator is zero.\n");
abort();
}
if (fmpz_poly_is_one(rop->den))
return;
fmpz_poly_init(gcd);
fmpz_poly_gcd(gcd, rop->num, rop->den);
if (!fmpz_poly_is_unit(gcd))
{
fmpz_poly_div(rop->num, rop->num, gcd);
fmpz_poly_div(rop->den, rop->den, gcd);
}
fmpz_poly_clear(gcd);
if (fmpz_sgn(fmpz_poly_lead(rop->den)) < 0)
{
fmpz_poly_neg(rop->num, rop->num);
fmpz_poly_neg(rop->den, rop->den);
}
}
void
fmpz_poly_bit_pack(fmpz_t f, const fmpz_poly_t poly,
mp_bitcnt_t bit_size)
{
long len;
__mpz_struct * mpz;
long i, d;
int negate;
len = fmpz_poly_length(poly);
if (len == 0 || bit_size == 0)
{
fmpz_zero(f);
return;
}
mpz = _fmpz_promote(f);
mpz_realloc2(mpz, len * bit_size);
d = mpz->_mp_alloc;
mpn_zero(mpz->_mp_d, d);
if (fmpz_sgn(fmpz_poly_lead(poly)) < 0)
negate = -1;
else
negate = 0;
_fmpz_poly_bit_pack(mpz->_mp_d, poly->coeffs, len, bit_size, negate);
for (i = d - 1; i >= 0; i--)
{
if (mpz->_mp_d[i] != 0)
break;
}
d = i + 1;
mpz->_mp_size = d;
_fmpz_demote_val(f);
if (negate)
fmpz_neg(f, f);
}
void fmpz_mod_poly_divrem_f(fmpz_t f, fmpz_mod_poly_t Q, fmpz_mod_poly_t R,
const fmpz_mod_poly_t A, const fmpz_mod_poly_t B)
{
const slong lenA = A->length;
const slong lenB = B->length;
const slong lenQ = lenA - lenB + 1;
fmpz *q, *r;
fmpz_t invB;
fmpz_init(invB);
fmpz_gcdinv(f, invB, fmpz_poly_lead(B), &(B->p));
if (!fmpz_is_one(f))
{
fmpz_clear(invB);
return;
}
if (lenA < lenB)
{
fmpz_mod_poly_set(R, A);
fmpz_mod_poly_zero(Q);
fmpz_clear(invB);
return;
}
if (Q == A || Q == B)
{
q = _fmpz_vec_init(lenQ);
}
else
{
fmpz_mod_poly_fit_length(Q, lenQ);
q = Q->coeffs;
}
if (R == A || R == B)
{
r = _fmpz_vec_init(lenA);
}
else
{
fmpz_mod_poly_fit_length(R, lenA);
r = R->coeffs;
}
_fmpz_mod_poly_divrem_divconquer(q, r, A->coeffs, lenA,
B->coeffs, lenB, invB, &(B->p));
if (Q == A || Q == B)
{
_fmpz_vec_clear(Q->coeffs, Q->alloc);
Q->coeffs = q;
Q->alloc = lenQ;
Q->length = lenQ;
}
else
{
_fmpz_mod_poly_set_length(Q, lenQ);
}
if (R == A || R == B)
{
_fmpz_vec_clear(R->coeffs, R->alloc);
R->coeffs = r;
R->alloc = lenA;
R->length = lenA;
}
_fmpz_mod_poly_set_length(R, lenB - 1);
_fmpz_mod_poly_normalise(R);
fmpz_clear(invB);
}
long _fmpz_poly_hensel_start_lift(fmpz_poly_factor_t lifted_fac, long *link,
fmpz_poly_t *v, fmpz_poly_t *w, const fmpz_poly_t f,
const nmod_poly_factor_t local_fac, long N)
{
const long r = local_fac->num;
long i, preve;
fmpz_t p, P;
fmpz_poly_t monic_f;
fmpz_init(p);
fmpz_init(P);
fmpz_poly_init(monic_f);
fmpz_set_ui(p, (local_fac->p + 0)->mod.n);
fmpz_pow_ui(P, p, N);
if (fmpz_is_one(fmpz_poly_lead(f)))
{
fmpz_poly_set(monic_f, f);
}
else if (fmpz_cmp_si(fmpz_poly_lead(f), -1) == 0)
{
fmpz_poly_neg(monic_f, f);
}
else
{
fmpz_t t;
fmpz_init(t);
fmpz_mod(t, fmpz_poly_lead(f), P);
if (fmpz_invmod(t, t, P) == 0)
{
printf("Exception in fmpz_poly_start_hensel_lift.\n");
abort();
}
fmpz_poly_scalar_mul_fmpz(monic_f, f, t);
fmpz_poly_scalar_mod_fmpz(monic_f, monic_f, P);
fmpz_clear(t);
}
fmpz_poly_hensel_build_tree(link, v, w, local_fac);
{
long *e, n = FLINT_CLOG2(N) + 1;
e = flint_malloc(n * sizeof(long));
for (e[i = 0] = N; e[i] > 1; i++)
e[i + 1] = (e[i] + 1) / 2;
for (i--; i > 0; i--)
{
fmpz_poly_hensel_lift_tree(link, v, w, monic_f, r,
p, e[i+1], e[i], 1);
}
if (N > 1)
{
fmpz_poly_hensel_lift_tree(link, v, w, monic_f, r,
p, e[i+1], e[i], 0);
}
preve = e[i+1];
flint_free(e);
}
/*
Now everything is lifted to p^N, we just need to
insert the factors into their correct places in lifted_fac.
*/
fmpz_poly_factor_fit_length(lifted_fac, r);
for (i = 0; i < 2*r - 2; i++)
{
if (link[i] < 0)
{
fmpz_poly_scalar_smod_fmpz(lifted_fac->p + (- link[i] - 1), v[i], P);
lifted_fac->exp[- link[i] - 1] = 1L;
}
}
lifted_fac->num = r;
fmpz_clear(p);
fmpz_clear(P);
fmpz_poly_clear(monic_f);
return preve;
}
int
main(void)
{
int i, result;
flint_rand_t state;
printf("hensel_start_continue_lift....");
fflush(stdout);
flint_randinit(state);
/* We check that lifting local factors of F yields factors */
for (i = 0; i < 1000; i++)
{
fmpz_poly_t F, G, H, R;
nmod_poly_factor_t f_fac;
fmpz_poly_factor_t F_fac;
long bits, nbits, n, exp, j, part_exp;
long r;
fmpz_poly_t *v, *w;
long *link;
long prev_exp;
bits = n_randint(state, 200) + 1;
nbits = n_randint(state, FLINT_BITS - 6) + 6;
fmpz_poly_init(F);
fmpz_poly_init(G);
fmpz_poly_init(H);
fmpz_poly_init(R);
nmod_poly_factor_init(f_fac);
fmpz_poly_factor_init(F_fac);
n = n_randprime(state, nbits, 0);
exp = bits / (FLINT_BIT_COUNT(n) - 1) + 1;
part_exp = n_randint(state, exp);
/* Produce F as the product of random G and H */
{
nmod_poly_t f;
nmod_poly_init(f, n);
do {
do {
fmpz_poly_randtest(G, state, n_randint(state, 200) + 2, bits);
} while (G->length < 2);
fmpz_randtest_not_zero(G->coeffs, state, bits);
fmpz_one(fmpz_poly_lead(G));
do {
fmpz_poly_randtest(H, state, n_randint(state, 200) + 2, bits);
} while (H->length < 2);
fmpz_randtest_not_zero(H->coeffs, state, bits);
fmpz_one(fmpz_poly_lead(H));
fmpz_poly_mul(F, G, H);
fmpz_poly_get_nmod_poly(f, F);
} while (!nmod_poly_is_squarefree(f));
fmpz_poly_get_nmod_poly(f, G);
nmod_poly_factor_insert(f_fac, f, 1);
fmpz_poly_get_nmod_poly(f, H);
nmod_poly_factor_insert(f_fac, f, 1);
nmod_poly_clear(f);
}
r = f_fac->num;
v = flint_malloc((2*r - 2)*sizeof(fmpz_poly_t));
w = flint_malloc((2*r - 2)*sizeof(fmpz_poly_t));
link = flint_malloc((2*r - 2)*sizeof(long));
for (j = 0; j < 2*r - 2; j++)
{
fmpz_poly_init(v[j]);
fmpz_poly_init(w[j]);
}
if (part_exp < 1)
{
_fmpz_poly_hensel_start_lift(F_fac, link, v, w, F, f_fac, exp);
}
else
{
fmpz_t nn;
fmpz_init_set_ui(nn, n);
prev_exp = _fmpz_poly_hensel_start_lift(F_fac, link, v, w,
F, f_fac, part_exp);
_fmpz_poly_hensel_continue_lift(F_fac, link, v, w,
F, prev_exp, part_exp, exp, nn);
fmpz_clear(nn);
}
result = 1;
for (j = 0; j < F_fac->num; j++)
{
fmpz_poly_rem(R, F, F_fac->p + j);
result &= (R->length == 0);
}
for (j = 0; j < 2*r - 2; j++)
{
fmpz_poly_clear(v[j]);
fmpz_poly_clear(w[j]);
}
flint_free(link);
flint_free(v);
flint_free(w);
if (!result)
{
printf("FAIL:\n");
printf("bits = %ld, n = %ld, exp = %ld\n", bits, n, exp);
fmpz_poly_print(F); printf("\n\n");
fmpz_poly_print(G); printf("\n\n");
fmpz_poly_print(H); printf("\n\n");
fmpz_poly_factor_print(F_fac); printf("\n\n");
abort();
}
nmod_poly_factor_clear(f_fac);
fmpz_poly_factor_clear(F_fac);
fmpz_poly_clear(F);
fmpz_poly_clear(H);
fmpz_poly_clear(G);
fmpz_poly_clear(R);
}
flint_randclear(state);
_fmpz_cleanup();
printf("PASS\n");
return 0;
}
