static void
poly_mod2_to_modq(fmpz_poly_t Fq,
const fmpz_poly_t a,
const ntru_params *params)
{
int v = 2;
fmpz_poly_t poly_tmp, two;
fmpz_poly_init(poly_tmp);
fmpz_poly_zero(poly_tmp);
fmpz_poly_init(two);
fmpz_poly_set_coeff_ui(two, 0, 2);
while (v < (int)(params->q)) {
v = v * 2;
poly_starmultiply(poly_tmp, a, Fq, params, v);
fmpz_poly_sub(poly_tmp, two, poly_tmp);
fmpz_poly_mod_unsigned(poly_tmp, v);
poly_starmultiply(Fq, Fq, poly_tmp, params, v);
}
fmpz_poly_clear(poly_tmp);
fmpz_poly_clear(two);
}
int
main(void)
{
int i, result;
flint_rand_t state;
printf("revert_series....");
fflush(stdout);
flint_randinit(state);
/* Check aliasing */
for (i = 0; i < 50; i++)
{
fmpz_poly_t f, g;
long n;
fmpz_poly_init(f);
fmpz_poly_init(g);
fmpz_poly_randtest(g, state, n_randint(state, 50),
1+n_randint(state,100));
fmpz_poly_set_coeff_ui(g, 0, 0);
fmpz_poly_set_coeff_ui(g, 1, 1);
if (n_randlimb(state) % 2)
fmpz_poly_neg(g, g); /* get -x term */
n = n_randint(state, 50);
fmpz_poly_revert_series(f, g, n);
fmpz_poly_revert_series(g, g, n);
result = (fmpz_poly_equal(f, g));
if (!result)
{
printf("FAIL (aliasing):\n");
fmpz_poly_print(f), printf("\n\n");
fmpz_poly_print(g), printf("\n\n");
abort();
}
fmpz_poly_clear(f);
fmpz_poly_clear(g);
}
/* Check f(f^(-1)) = id */
for (i = 0; i < 50; i++)
{
fmpz_poly_t f, g, h;
long n;
fmpz_poly_init(f);
fmpz_poly_init(g);
fmpz_poly_init(h);
fmpz_poly_randtest(g, state, n_randint(state, 50), 10);
fmpz_poly_set_coeff_ui(g, 0, 0);
fmpz_poly_set_coeff_ui(g, 1, 1);
if (n_randlimb(state) % 2)
fmpz_poly_neg(g, g); /* get -x term */
n = n_randint(state, 50);
fmpz_poly_revert_series(f, g, n);
fmpz_poly_compose_series(h, g, f, n);
result = ((n <= 1 && fmpz_poly_is_zero(h)) ||
(h->length == 2 && fmpz_is_zero(h->coeffs + 0) &&
fmpz_is_one(h->coeffs + 1)));
if (!result)
{
printf("FAIL (comparison):\n");
fmpz_poly_print(f), printf("\n\n");
fmpz_poly_print(g), printf("\n\n");
fmpz_poly_print(h), printf("\n\n");
abort();
}
fmpz_poly_clear(f);
fmpz_poly_clear(g);
fmpz_poly_clear(h);
}
flint_randclear(state);
_fmpz_cleanup();
printf("PASS\n");
return 0;
}
int
main(void)
{
int i, result;
FLINT_TEST_INIT(state);
flint_printf("revert_series_lagrange_fast....");
fflush(stdout);
/* Check aliasing */
for (i = 0; i < 10 * flint_test_multiplier(); i++)
{
fmpz_poly_t f, g;
slong n;
fmpz_poly_init(f);
fmpz_poly_init(g);
fmpz_poly_randtest(g, state, n_randint(state, 50),
1+n_randint(state,100));
fmpz_poly_set_coeff_ui(g, 0, 0);
fmpz_poly_set_coeff_ui(g, 1, 1);
if (n_randlimb(state) % 2)
fmpz_poly_neg(g, g); /* get -x term */
n = n_randint(state, 50);
fmpz_poly_revert_series_lagrange_fast(f, g, n);
fmpz_poly_revert_series_lagrange_fast(g, g, n);
result = (fmpz_poly_equal(f, g));
if (!result)
{
flint_printf("FAIL (aliasing):\n");
fmpz_poly_print(f), flint_printf("\n\n");
fmpz_poly_print(g), flint_printf("\n\n");
abort();
}
fmpz_poly_clear(f);
fmpz_poly_clear(g);
}
/* Check f(f^(-1)) = id */
for (i = 0; i < 10 * flint_test_multiplier(); i++)
{
fmpz_poly_t f, g, h;
slong n;
fmpz_poly_init(f);
fmpz_poly_init(g);
fmpz_poly_init(h);
fmpz_poly_randtest(g, state, n_randint(state, 50), 1+n_randint(state,100));
fmpz_poly_set_coeff_ui(g, 0, 0);
fmpz_poly_set_coeff_ui(g, 1, 1);
if (n_randlimb(state) % 2)
fmpz_poly_neg(g, g); /* get -x term */
n = n_randint(state, 50);
fmpz_poly_revert_series_lagrange_fast(f, g, n);
fmpz_poly_compose_series(h, g, f, n);
result = ((n <= 1 && fmpz_poly_is_zero(h)) ||
(h->length == 2 && fmpz_is_zero(h->coeffs + 0) &&
fmpz_is_one(h->coeffs + 1)));
if (!result)
{
flint_printf("FAIL (comparison):\n");
fmpz_poly_print(f), flint_printf("\n\n");
fmpz_poly_print(g), flint_printf("\n\n");
fmpz_poly_print(h), flint_printf("\n\n");
abort();
}
fmpz_poly_clear(f);
fmpz_poly_clear(g);
fmpz_poly_clear(h);
}
FLINT_TEST_CLEANUP(state);
flint_printf("PASS\n");
return 0;
}
int
main(void)
{
int i;
FLINT_TEST_INIT(state);
flint_printf("taylor_shift_divconquer....");
fflush(stdout);
/* Check aliasing */
for (i = 0; i < 100 * flint_test_multiplier(); i++)
{
fmpz_poly_t f, g;
fmpz_t c;
fmpz_poly_init(f);
fmpz_poly_init(g);
fmpz_init(c);
fmpz_poly_randtest(f, state, 1 + n_randint(state, 20),
1 + n_randint(state, 200));
fmpz_randtest(c, state, n_randint(state, 200));
fmpz_poly_taylor_shift_divconquer(g, f, c);
fmpz_poly_taylor_shift_divconquer(f, f, c);
if (!fmpz_poly_equal(g, f))
{
flint_printf("FAIL\n");
fmpz_poly_print(f); flint_printf("\n");
fmpz_poly_print(g); flint_printf("\n");
abort();
}
fmpz_poly_clear(f);
fmpz_poly_clear(g);
fmpz_clear(c);
}
/* Compare with composition */
for (i = 0; i < 100 * flint_test_multiplier(); i++)
{
fmpz_poly_t f, g, h1, h2;
fmpz_t c;
fmpz_poly_init(f);
fmpz_poly_init(g);
fmpz_poly_init(h1);
fmpz_poly_init(h2);
fmpz_init(c);
fmpz_poly_randtest(f, state, 1 + n_randint(state, 20),
1 + n_randint(state, 200));
fmpz_randtest(c, state, n_randint(state, 200));
fmpz_poly_set_coeff_ui(g, 1, 1);
fmpz_poly_set_coeff_fmpz(g, 0, c);
fmpz_poly_taylor_shift_divconquer(h1, f, c);
fmpz_poly_compose(h2, f, g);
if (!fmpz_poly_equal(h1, h2))
{
flint_printf("FAIL\n");
fmpz_poly_print(f); flint_printf("\n");
fmpz_poly_print(g); flint_printf("\n");
fmpz_poly_print(h1); flint_printf("\n");
fmpz_poly_print(h2); flint_printf("\n");
abort();
}
fmpz_poly_clear(f);
fmpz_poly_clear(g);
fmpz_poly_clear(h1);
fmpz_poly_clear(h2);
fmpz_clear(c);
}
FLINT_TEST_CLEANUP(state);
flint_printf("PASS\n");
return 0;
}
int main(int argc, char *argv[])
{
fmpz_poly_t f, g;
fmpz_poly_factor_t fac;
fmpz_t t;
slong compd, printd, i, j;
if (argc < 2)
{
flint_printf("poly_roots [-refine d] [-print d] <poly>\n\n");
flint_printf("Isolates all the complex roots of a polynomial with integer coefficients.\n\n");
flint_printf("If -refine d is passed, the roots are refined to an absolute tolerance\n");
flint_printf("better than 10^(-d). By default, the roots are only computed to sufficient\n");
flint_printf("accuracy to isolate them. The refinement is not currently done efficiently.\n\n");
flint_printf("If -print d is passed, the computed roots are printed to d decimals.\n");
flint_printf("By default, the roots are not printed.\n\n");
flint_printf("The polynomial can be specified by passing the following as <poly>:\n\n");
flint_printf("a <n> Easy polynomial 1 + 2x + ... + (n+1)x^n\n");
flint_printf("t <n> Chebyshev polynomial T_n\n");
flint_printf("u <n> Chebyshev polynomial U_n\n");
flint_printf("p <n> Legendre polynomial P_n\n");
flint_printf("c <n> Cyclotomic polynomial Phi_n\n");
flint_printf("s <n> Swinnerton-Dyer polynomial S_n\n");
flint_printf("b <n> Bernoulli polynomial B_n\n");
flint_printf("w <n> Wilkinson polynomial W_n\n");
flint_printf("e <n> Taylor series of exp(x) truncated to degree n\n");
flint_printf("m <n> <m> The Mignotte-like polynomial x^n + (100x+1)^m, n > m\n");
flint_printf("coeffs <c0 c1 ... cn> c0 + c1 x + ... + cn x^n\n\n");
flint_printf("Concatenate to multiply polynomials, e.g.: p 5 t 6 coeffs 1 2 3\n");
flint_printf("for P_5(x)*T_6(x)*(1+2x+3x^2)\n\n");
return 1;
}
compd = 0;
printd = 0;
fmpz_poly_init(f);
fmpz_poly_init(g);
fmpz_init(t);
fmpz_poly_one(f);
for (i = 1; i < argc; i++)
{
if (!strcmp(argv[i], "-refine"))
{
compd = atol(argv[i+1]);
i++;
}
else if (!strcmp(argv[i], "-print"))
{
printd = atol(argv[i+1]);
i++;
}
else if (!strcmp(argv[i], "a"))
{
slong n = atol(argv[i+1]);
fmpz_poly_zero(g);
for (j = 0; j <= n; j++)
fmpz_poly_set_coeff_ui(g, j, j+1);
fmpz_poly_mul(f, f, g);
i++;
}
else if (!strcmp(argv[i], "t"))
{
arith_chebyshev_t_polynomial(g, atol(argv[i+1]));
fmpz_poly_mul(f, f, g);
i++;
}
else if (!strcmp(argv[i], "u"))
{
arith_chebyshev_u_polynomial(g, atol(argv[i+1]));
fmpz_poly_mul(f, f, g);
i++;
}
else if (!strcmp(argv[i], "p"))
{
fmpq_poly_t h;
fmpq_poly_init(h);
arith_legendre_polynomial(h, atol(argv[i+1]));
fmpq_poly_get_numerator(g, h);
fmpz_poly_mul(f, f, g);
fmpq_poly_clear(h);
i++;
}
else if (!strcmp(argv[i], "c"))
{
arith_cyclotomic_polynomial(g, atol(argv[i+1]));
fmpz_poly_mul(f, f, g);
i++;
}
else if (!strcmp(argv[i], "s"))
{
arith_swinnerton_dyer_polynomial(g, atol(argv[i+1]));
fmpz_poly_mul(f, f, g);
i++;
}
else if (!strcmp(argv[i], "b"))
{
fmpq_poly_t h;
fmpq_poly_init(h);
arith_bernoulli_polynomial(h, atol(argv[i+1]));
fmpq_poly_get_numerator(g, h);
fmpz_poly_mul(f, f, g);
fmpq_poly_clear(h);
i++;
}
else if (!strcmp(argv[i], "w"))
{
slong n = atol(argv[i+1]);
fmpz_poly_zero(g);
fmpz_poly_fit_length(g, n+2);
arith_stirling_number_1_vec(g->coeffs, n+1, n+2);
_fmpz_poly_set_length(g, n+2);
fmpz_poly_shift_right(g, g, 1);
fmpz_poly_mul(f, f, g);
i++;
}
else if (!strcmp(argv[i], "e"))
{
fmpq_poly_t h;
fmpq_poly_init(h);
fmpq_poly_set_coeff_si(h, 0, 0);
fmpq_poly_set_coeff_si(h, 1, 1);
fmpq_poly_exp_series(h, h, atol(argv[i+1]) + 1);
fmpq_poly_get_numerator(g, h);
fmpz_poly_mul(f, f, g);
fmpq_poly_clear(h);
i++;
}
else if (!strcmp(argv[i], "m"))
{
fmpz_poly_zero(g);
fmpz_poly_set_coeff_ui(g, 0, 1);
fmpz_poly_set_coeff_ui(g, 1, 100);
fmpz_poly_pow(g, g, atol(argv[i+2]));
fmpz_poly_set_coeff_ui(g, atol(argv[i+1]), 1);
fmpz_poly_mul(f, f, g);
i += 2;
}
else if (!strcmp(argv[i], "coeffs"))
{
fmpz_poly_zero(g);
i++;
j = 0;
while (i < argc)
{
if (fmpz_set_str(t, argv[i], 10) != 0)
{
i--;
break;
}
fmpz_poly_set_coeff_fmpz(g, j, t);
i++;
j++;
}
fmpz_poly_mul(f, f, g);
}
}
fmpz_poly_factor_init(fac);
flint_printf("computing squarefree factorization...\n");
TIMEIT_ONCE_START
fmpz_poly_factor_squarefree(fac, f);
TIMEIT_ONCE_STOP
TIMEIT_ONCE_START
for (i = 0; i < fac->num; i++)
{
flint_printf("roots with multiplicity %wd\n", fac->exp[i]);
fmpz_poly_complex_roots_squarefree(fac->p + i,
32, compd * 3.32193 + 2, printd);
}
TIMEIT_ONCE_STOP
fmpz_poly_factor_clear(fac);
fmpz_poly_clear(f);
fmpz_poly_clear(g);
fmpz_clear(t);
flint_cleanup();
return EXIT_SUCCESS;
}
bool
poly_inverse_poly_p(fmpz_poly_t Fp,
const fmpz_poly_t a,
const ntru_params *params)
{
bool retval = false;
int k = 0,
j = 0;
fmpz *b_last;
fmpz_poly_t a_tmp,
b,
c,
f,
g;
/* general initialization of temp variables */
fmpz_poly_init(b);
fmpz_poly_set_coeff_ui(b, 0, 1);
fmpz_poly_init(c);
fmpz_poly_init(f);
fmpz_poly_set(f, a);
/* set g(x) = x^N − 1 */
fmpz_poly_init(g);
fmpz_poly_set_coeff_si(g, 0, -1);
fmpz_poly_set_coeff_si(g, params->N, 1);
/* avoid side effects */
fmpz_poly_init(a_tmp);
fmpz_poly_set(a_tmp, a);
fmpz_poly_zero(Fp);
while (1) {
while (fmpz_poly_get_coeff_ptr(f, 0) &&
fmpz_is_zero(fmpz_poly_get_coeff_ptr(f, 0))) {
for (uint32_t i = 1; i <= params->N; i++) {
fmpz *f_coeff = fmpz_poly_get_coeff_ptr(f, i);
fmpz *c_coeff = fmpz_poly_get_coeff_ptr(c, params->N - i);
/* f(x) = f(x) / x */
fmpz_poly_set_coeff_fmpz_n(f, i - 1,
f_coeff);
/* c(x) = c(x) * x */
fmpz_poly_set_coeff_fmpz_n(c, params->N + 1 - i,
c_coeff);
}
fmpz_poly_set_coeff_si(f, params->N, 0);
fmpz_poly_set_coeff_si(c, 0, 0);
k++;
if (fmpz_poly_degree(f) == -1)
goto cleanup;
}
if (fmpz_poly_is_zero(g) == 1)
goto cleanup;
if (fmpz_poly_degree(f) == 0)
break;
if (fmpz_poly_degree(f) < fmpz_poly_degree(g)) {
/* exchange f and g and exchange b and c */
fmpz_poly_swap(f, g);
fmpz_poly_swap(b, c);
}
{
fmpz_poly_t c_tmp,
g_tmp;
fmpz_t u,
mp_tmp;
fmpz_init(u);
fmpz_zero(u);
fmpz_init_set(mp_tmp, fmpz_poly_get_coeff_ptr(f, 0));
fmpz_poly_init(g_tmp);
fmpz_poly_set(g_tmp, g);
fmpz_poly_init(c_tmp);
fmpz_poly_set(c_tmp, c);
/* u = f[0] * g[0]^(-1) mod p */
/* = (f[0] mod p) * (g[0] inverse mod p) mod p */
fmpz_invmod_ui(u,
fmpz_poly_get_coeff_ptr(g, 0),
params->p);
fmpz_mod_ui(mp_tmp, mp_tmp, params->p);
fmpz_mul(u, mp_tmp, u);
fmpz_mod_ui(u, u, params->p);
/* f = f - u * g mod p */
fmpz_poly_scalar_mul_fmpz(g_tmp, g_tmp, u);
fmpz_poly_sub(f, f, g_tmp);
fmpz_poly_mod_unsigned(f, params->p);
/* b = b - u * c mod p */
fmpz_poly_scalar_mul_fmpz(c_tmp, c_tmp, u);
fmpz_poly_sub(b, b, c_tmp);
fmpz_poly_mod_unsigned(b, params->p);
fmpz_clear(u);
fmpz_poly_clear(g_tmp);
fmpz_poly_clear(c_tmp);
}
}
k = k % params->N;
b_last = fmpz_poly_get_coeff_ptr(b, params->N);
if (fmpz_cmp_si_n(b_last, 0))
goto cleanup;
/* Fp(x) = x^(N-k) * b(x) */
for (int i = params->N - 1; i >= 0; i--) {
fmpz *b_i;
/* b(X) = f[0]^(-1) * b(X) (mod p) */
{
fmpz_t mp_tmp;
fmpz_init(mp_tmp);
fmpz_invmod_ui(mp_tmp,
fmpz_poly_get_coeff_ptr(f, 0),
params->p);
if (fmpz_poly_get_coeff_ptr(b, i)) {
fmpz_mul(fmpz_poly_get_coeff_ptr(b, i),
fmpz_poly_get_coeff_ptr(b, i),
mp_tmp);
fmpz_mod_ui(fmpz_poly_get_coeff_ptr(b, i),
fmpz_poly_get_coeff_ptr(b, i),
params->p);
}
}
j = i - k;
if (j < 0)
j = j + params->N;
b_i = fmpz_poly_get_coeff_ptr(b, i);
fmpz_poly_set_coeff_fmpz_n(Fp, j, b_i);
}
/* check if the f * Fp = 1 (mod p) condition holds true */
fmpz_poly_set(a_tmp, a);
poly_starmultiply(a_tmp, a_tmp, Fp, params, params->p);
if (fmpz_poly_is_one(a_tmp))
retval = true;
else
fmpz_poly_zero(Fp);
cleanup:
fmpz_poly_clear(a_tmp);
fmpz_poly_clear(b);
fmpz_poly_clear(c);
fmpz_poly_clear(f);
fmpz_poly_clear(g);
return retval;
}
bool
poly_inverse_poly_q(fmpz_poly_t Fq,
const fmpz_poly_t a,
const ntru_params *params)
{
bool retval = false;
int k = 0,
j = 0;
fmpz *b_last;
fmpz_poly_t a_tmp,
b,
c,
f,
g;
/* general initialization of temp variables */
fmpz_poly_init(b);
fmpz_poly_set_coeff_ui(b, 0, 1);
fmpz_poly_init(c);
fmpz_poly_init(f);
fmpz_poly_set(f, a);
/* set g(x) = x^N − 1 */
fmpz_poly_init(g);
fmpz_poly_set_coeff_si(g, 0, -1);
fmpz_poly_set_coeff_si(g, params->N, 1);
/* avoid side effects */
fmpz_poly_init(a_tmp);
fmpz_poly_set(a_tmp, a);
fmpz_poly_zero(Fq);
while (1) {
while (fmpz_poly_get_coeff_ptr(f, 0) &&
fmpz_is_zero(fmpz_poly_get_coeff_ptr(f, 0))) {
for (uint32_t i = 1; i <= params->N; i++) {
fmpz *f_coeff = fmpz_poly_get_coeff_ptr(f, i);
fmpz *c_coeff = fmpz_poly_get_coeff_ptr(c, params->N - i);
/* f(x) = f(x) / x */
fmpz_poly_set_coeff_fmpz_n(f, i - 1,
f_coeff);
/* c(x) = c(x) * x */
fmpz_poly_set_coeff_fmpz_n(c, params->N + 1 - i,
c_coeff);
}
fmpz_poly_set_coeff_si(f, params->N, 0);
fmpz_poly_set_coeff_si(c, 0, 0);
k++;
if (fmpz_poly_degree(f) == -1)
goto cleanup;
}
if (fmpz_poly_is_zero(g) == 1)
goto cleanup;
if (fmpz_poly_degree(f) == 0)
break;
if (fmpz_poly_degree(f) < fmpz_poly_degree(g)) {
fmpz_poly_swap(f, g);
fmpz_poly_swap(b, c);
}
fmpz_poly_add(f, g, f);
fmpz_poly_mod_unsigned(f, 2);
fmpz_poly_add(b, c, b);
fmpz_poly_mod_unsigned(b, 2);
}
k = k % params->N;
b_last = fmpz_poly_get_coeff_ptr(b, params->N);
if (fmpz_cmp_si_n(b_last, 0))
goto cleanup;
/* Fq(x) = x^(N-k) * b(x) */
for (int i = params->N - 1; i >= 0; i--) {
fmpz *b_i;
j = i - k;
if (j < 0)
j = j + params->N;
b_i = fmpz_poly_get_coeff_ptr(b, i);
fmpz_poly_set_coeff_fmpz_n(Fq, j, b_i);
}
poly_mod2_to_modq(Fq, a_tmp, params);
/* check if the f * Fq = 1 (mod p) condition holds true */
fmpz_poly_set(a_tmp, a);
poly_starmultiply(a_tmp, a_tmp, Fq, params, params->q);
if (fmpz_poly_is_one(a_tmp))
retval = true;
else
fmpz_poly_zero(Fq);
cleanup:
fmpz_poly_clear(a_tmp);
fmpz_poly_clear(b);
fmpz_poly_clear(c);
fmpz_poly_clear(f);
fmpz_poly_clear(g);
return retval;
}
int
main(void)
{
int i, result;
FLINT_TEST_INIT(state);
flint_printf("compose_series....");
fflush(stdout);
/* Check aliasing of the first argument */
for (i = 0; i < 10 * flint_test_multiplier(); i++)
{
fmpz_poly_t f, g, h;
slong n;
fmpz_poly_init(f);
fmpz_poly_init(g);
fmpz_poly_init(h);
fmpz_poly_randtest(g, state, n_randint(state, 40), 80);
fmpz_poly_randtest(h, state, n_randint(state, 20), 50);
fmpz_poly_set_coeff_ui(h, 0, 0);
n = n_randint(state, 20);
fmpz_poly_compose_series(f, g, h, n);
fmpz_poly_compose_series(g, g, h, n);
result = (fmpz_poly_equal(f, g));
if (!result)
{
flint_printf("FAIL (aliasing 1):\n");
fmpz_poly_print(f), flint_printf("\n\n");
fmpz_poly_print(g), flint_printf("\n\n");
abort();
}
fmpz_poly_clear(f);
fmpz_poly_clear(g);
fmpz_poly_clear(h);
}
/* Check aliasing of the second argument */
for (i = 0; i < 10 * flint_test_multiplier(); i++)
{
fmpz_poly_t f, g, h;
slong n;
fmpz_poly_init(f);
fmpz_poly_init(g);
fmpz_poly_init(h);
fmpz_poly_randtest(g, state, n_randint(state, 40), 80);
fmpz_poly_randtest(h, state, n_randint(state, 20), 50);
fmpz_poly_set_coeff_ui(h, 0, 0);
n = n_randint(state, 20);
fmpz_poly_compose_series(f, g, h, n);
fmpz_poly_compose_series(h, g, h, n);
result = (fmpz_poly_equal(f, h));
if (!result)
{
flint_printf("FAIL (aliasing 2):\n");
fmpz_poly_print(f), flint_printf("\n\n");
fmpz_poly_print(h), flint_printf("\n\n");
abort();
}
fmpz_poly_clear(f);
fmpz_poly_clear(g);
fmpz_poly_clear(h);
}
/* Compare with compose */
for (i = 0; i < 10 * flint_test_multiplier(); i++)
{
fmpz_poly_t f, g, h, s, t;
slong n;
fmpz_poly_init(f);
fmpz_poly_init(g);
fmpz_poly_init(h);
fmpz_poly_init(s);
fmpz_poly_init(t);
fmpz_poly_randtest(g, state, n_randint(state, 40), 80);
fmpz_poly_randtest(h, state, n_randint(state, 20), 50);
fmpz_poly_set_coeff_ui(h, 0, 0);
n = n_randint(state, 10);
fmpz_poly_compose(s, g, h);
fmpz_poly_truncate(s, n);
fmpz_poly_compose_series(f, g, h, n);
result = (fmpz_poly_equal(f, s));
if (!result)
{
flint_printf("FAIL (comparison):\n");
flint_printf("n = %wd\n", n);
flint_printf("g = "), fmpz_poly_print(g), flint_printf("\n\n");
flint_printf("h = "), fmpz_poly_print(h), flint_printf("\n\n");
flint_printf("f = "), fmpz_poly_print(f), flint_printf("\n\n");
flint_printf("s = "), fmpz_poly_print(s), flint_printf("\n\n");
abort();
}
fmpz_poly_clear(f);
fmpz_poly_clear(g);
fmpz_poly_clear(h);
fmpz_poly_clear(s);
fmpz_poly_clear(t);
}
FLINT_TEST_CLEANUP(state);
flint_printf("PASS\n");
return 0;
}
// Version Fq
void fq_poly_compose_mod_kedlaya_umans(fq_poly_t fg, const fq_poly_t f, const fq_poly_t g, const fq_poly_t h, slong d, fq_ctx_t ctx) {
slong n, i, j, m, dm, N, Nm, degree;
fmpz* p;
fmpz_t q;
fq_multi_poly_t f_prime;
fq_struct *vect_beta, *vect_alpha, *vect_alpha2, *vect_eval;
fq_poly_t gi;
// Vérification des paramètres
n = FLINT_MAX(fq_poly_length(f,ctx),fq_poly_length(g,ctx));
i = fq_poly_length(h,ctx);
if(n >= i) {
printf("Erreur, f ou g n'a pas été modulé par h.\n");
exit(1);
}
// Les polynômes f et g étant réduits modulo h, n vaut le nombre de coefficients de h
n = i;
if(d < 2) {
printf("d < 2\n");
exit(1);
}
if(d >= n) {
printf("d >= n\n");
exit(1);
}
p = fq_ctx_prime(ctx);
degree = fq_ctx_degree(ctx);
m = n_clog(n,d);
dm = n_pow(d,m);
N = n_pow(d,m)*m*d;
Nm = N*m;
if(fmpz_cmp_ui(p,N) < 0) {
flint_printf("\nErreur, pas assez de points d'interpolation !\n");
flint_printf("\np tient sur un mot machine, utilisez donc la version fq_nmod !\n");
exit(1);
}
// Étape 1 //////////////////////////////
fq_multi_poly_init(f_prime, dm, d, m, ctx);
_fq_vec_zero(f_prime->poly, dm, ctx);
for(i = 0 ; i < n ; i++) {
fq_poly_get_coeff(&(f_prime->poly[i]),f,i,ctx);
}
// Étape 3 //////////////////////////////
vect_beta = _fq_vec_init(N,ctx);
for(i = 0 ; i < N ; i++) {
fmpz_poly_set_coeff_ui(vect_beta + i, 0, i);
}
vect_alpha = _fq_vec_init(N*m, ctx);
fq_poly_init(gi,ctx);
fq_poly_set(gi,g,ctx);
fq_poly_evaluate_fq_vec(vect_alpha, gi, vect_beta, N, ctx);
for(i = 1 ; i < m ; i++) {
// Étape 2 //////////////////////////////
// Calcul du g^(d^i) avec g^(d^i) = [ (g^(d^(i-1))) ^ d ] mod h
fq_poly_powmod_ui_binexp(gi,gi,d,h,ctx);
fq_poly_evaluate_fq_vec(vect_alpha+i*N, gi, vect_beta, N, ctx);
}
fq_poly_clear(gi, ctx);
// Transposition
// Passe de m lignes N colonnes
// à N lignes m colonnes ==> nécessaire pour EMM dans Fp
vect_alpha2 = _fq_vec_init(Nm,ctx);
for(i = 0 ; i < m ; i++) {
for(j = 0 ; j < N ; j++) {
fq_set(vect_alpha2 + j*m + i,vect_alpha + i*N + j,ctx);
}
}
vect_alpha = vect_alpha2;
// Étape 4 //////////////////////////////
// EMM
vect_eval = _fq_vec_init(N,ctx);
fq_multi_poly_multimodular(vect_eval, N, f_prime, vect_alpha, ctx);
_fq_vec_clear(vect_alpha,Nm,ctx);
fq_multi_poly_clear(f_prime,ctx);
// Étape 5 //////////////////////////////
fq_poly_interpolate_fq_vec_fast(fg, vect_beta, vect_eval, N, ctx);
_fq_vec_clear(vect_beta,N,ctx);
_fq_vec_clear(vect_eval,N,ctx);
// Étape 6 //////////////////////////////
fq_poly_rem(fg,fg,h,ctx);
}
