int main (void) { double t; nmod_poly_t f, g, h; for (int i= 15001;i < 16000; i++) { nmod_poly_init2 (f, 17, i/2+1); nmod_poly_init2 (g, 17, i+1); nmod_poly_set_coeff_ui (f, i/2, 1); nmod_poly_set_coeff_ui (f, 1, 1); nmod_poly_set_coeff_ui (f, 0, ((i%17)*(i%17)+3) % 17); nmod_poly_set_coeff_ui (g, i, 1); nmod_poly_set_coeff_ui (g, i/2+1, 1); nmod_poly_set_coeff_ui (g, 1, ((i % 17)+1)%17); nmod_poly_set_coeff_ui (g, 0, 15); nmod_poly_init (h, 17); nmod_poly_gcd (h, f, g); if (!nmod_poly_is_one (h)) { flint_printf ("i= %d\n", i); nmod_poly_factor_t factors; nmod_poly_factor_init (factors); t= clock(); nmod_poly_factor (factors, h); t = (clock() - t) / CLOCKS_PER_SEC; flint_printf("factorization %.2lf\n", t); nmod_poly_factor_clear (factors); } nmod_poly_clear (f); nmod_poly_clear (g); nmod_poly_clear (h); } return EXIT_SUCCESS; }
int main(void) { int iter; flint_rand_t state; flint_randinit(state); printf("factor...."); fflush(stdout); /* Default algorithm */ for (iter = 0; iter < 100; iter++) { int result = 1; nmod_poly_t pol1, poly, quot, rem, product; nmod_poly_factor_t res; mp_limb_t modulus, lead = 1; long length, num, i, j; ulong exp[5], prod1; modulus = n_randtest_prime(state, 0); nmod_poly_init(pol1, modulus); nmod_poly_init(poly, modulus); nmod_poly_init(quot, modulus); nmod_poly_init(rem, modulus); nmod_poly_zero(pol1); nmod_poly_set_coeff_ui(pol1, 0, 1); length = n_randint(state, 7) + 2; do { nmod_poly_randtest(poly, state, length); if (poly->length) nmod_poly_make_monic(poly, poly); } while ((!nmod_poly_is_irreducible(poly)) || (poly->length < 2)); exp[0] = n_randint(state, 30) + 1; prod1 = exp[0]; for (i = 0; i < exp[0]; i++) nmod_poly_mul(pol1, pol1, poly); num = n_randint(state, 5) + 1; for (i = 1; i < num; i++) { do { length = n_randint(state, 7) + 2; nmod_poly_randtest(poly, state, length); if (poly->length) { nmod_poly_make_monic(poly, poly); nmod_poly_divrem(quot, rem, pol1, poly); } } while ((!nmod_poly_is_irreducible(poly)) || (poly->length < 2) || (rem->length == 0)); exp[i] = n_randint(state, 30) + 1; prod1 *= exp[i]; for (j = 0; j < exp[i]; j++) nmod_poly_mul(pol1, pol1, poly); } nmod_poly_factor_init(res); switch (n_randint(state, 3)) { case 0: lead = nmod_poly_factor(res, pol1); break; case 1: lead = nmod_poly_factor_with_berlekamp(res, pol1); break; case 2: if (modulus == 2) lead = nmod_poly_factor(res, pol1); else lead = nmod_poly_factor_with_cantor_zassenhaus(res, pol1); break; } result &= (res->num == num); if (!result) { printf("Error: number of factors incorrect, %ld, %ld\n", res->num, num); abort(); } nmod_poly_init(product, pol1->mod.n); nmod_poly_set_coeff_ui(product, 0, 1); for (i = 0; i < res->num; i++) for (j = 0; j < res->exp[i]; j++) nmod_poly_mul(product, product, res->p + i); nmod_poly_scalar_mul_nmod(product, product, lead); result &= nmod_poly_equal(pol1, product); if (!result) { printf("Error: product of factors does not equal original polynomial\n"); nmod_poly_print(pol1); printf("\n"); nmod_poly_print(product); printf("\n"); abort(); } nmod_poly_clear(product); nmod_poly_clear(quot); nmod_poly_clear(rem); nmod_poly_clear(pol1); nmod_poly_clear(poly); nmod_poly_factor_clear(res); } /* Test deflation trick */ for (iter = 0; iter < 100; iter++) { nmod_poly_t pol1, poly, quot, rem; nmod_poly_factor_t res, res2; mp_limb_t modulus; long length, num, i, j; long exp[5], prod1; ulong inflation; int found; do { modulus = n_randtest_prime(state, 0); } while (modulus == 2); /* To compare with CZ */ nmod_poly_init(pol1, modulus); nmod_poly_init(poly, modulus); nmod_poly_init(quot, modulus); nmod_poly_init(rem, modulus); nmod_poly_zero(pol1); nmod_poly_set_coeff_ui(pol1, 0, 1); inflation = n_randint(state, 7) + 1; length = n_randint(state, 7) + 2; do { nmod_poly_randtest(poly, state, length); if (poly->length) nmod_poly_make_monic(poly, poly); } while ((!nmod_poly_is_irreducible(poly)) || (poly->length < 2)); nmod_poly_inflate(poly, poly, inflation); exp[0] = n_randint(state, 6) + 1; prod1 = exp[0]; for (i = 0; i < exp[0]; i++) nmod_poly_mul(pol1, pol1, poly); num = n_randint(state, 5) + 1; for (i = 1; i < num; i++) { do { length = n_randint(state, 6) + 2; nmod_poly_randtest(poly, state, length); if (poly->length) { nmod_poly_make_monic(poly, poly); nmod_poly_divrem(quot, rem, pol1, poly); } } while ((!nmod_poly_is_irreducible(poly)) || (poly->length < 2) || (rem->length == 0)); exp[i] = n_randint(state, 6) + 1; prod1 *= exp[i]; nmod_poly_inflate(poly, poly, inflation); for (j = 0; j < exp[i]; j++) nmod_poly_mul(pol1, pol1, poly); } nmod_poly_factor_init(res); nmod_poly_factor_init(res2); switch (n_randint(state, 3)) { case 0: nmod_poly_factor(res, pol1); break; case 1: nmod_poly_factor_with_berlekamp(res, pol1); break; case 2: nmod_poly_factor_with_cantor_zassenhaus(res, pol1); break; } nmod_poly_factor_cantor_zassenhaus(res2, pol1); if (res->num != res2->num) { printf("FAIL: different number of factors found\n"); abort(); } for (i = 0; i < res->num; i++) { found = 0; for (j = 0; j < res2->num; j++) { if (nmod_poly_equal(res->p + i, res2->p + j) && res->exp[i] == res2->exp[j]) { found = 1; break; } } if (!found) { printf("FAIL: factor not found\n"); abort(); } } nmod_poly_clear(quot); nmod_poly_clear(rem); nmod_poly_clear(pol1); nmod_poly_clear(poly); nmod_poly_factor_clear(res); nmod_poly_factor_clear(res2); } flint_randclear(state); printf("PASS\n"); return 0; }