Exemple #1
0
void
nmod_poly_randtest_monic_irreducible(nmod_poly_t poly, flint_rand_t state, slong len)
{
    do {
        nmod_poly_randtest_monic(poly, state, len);
    } while (nmod_poly_is_zero(poly) || !(nmod_poly_is_irreducible(poly)));
}
Exemple #2
0
int
nmod_poly_randtest_trinomial_irreducible(nmod_poly_t poly, flint_rand_t state,
                                         slong len, slong max_attempts)
{
    slong i = 0;

    while (max_attempts == 0 || i < max_attempts)
    {
        nmod_poly_randtest_trinomial(poly, state, len);
        if (!nmod_poly_is_zero(poly) && nmod_poly_is_irreducible(poly))
        {
            return 1;
        }
        i++;
        
    }
    return 0;
}
Exemple #3
0
int
main(void)
{
    int iter;
    FLINT_TEST_INIT(state);
    

    flint_printf("is_squarefree....");
    fflush(stdout);

    for (iter = 0; iter < 200 * flint_test_multiplier(); iter++)
    {
        nmod_poly_t poly, Q, R, t;
        mp_limb_t modulus;
        slong i, num_factors, exp, max_exp;
        int v, result;

        modulus = n_randtest_prime(state, 0);

        nmod_poly_init(poly, modulus);
        nmod_poly_init(t, modulus);
        nmod_poly_init(Q, modulus);
        nmod_poly_init(R, modulus);

        nmod_poly_set_coeff_ui(poly, 0, n_randint(state, modulus));
        num_factors = n_randint(state, 5);

        max_exp = 0;
        for (i = 0; i < num_factors; i++)
        {
            do {
                nmod_poly_randtest(t, state, n_randint(state, 10));
            } while (!nmod_poly_is_irreducible(t) ||
                    (nmod_poly_length(t) < 2));

            exp = n_randint(state, 4) + 1;
            if (n_randint(state, 2) == 0)
                exp = 1;

            nmod_poly_divrem(Q, R, poly, t);
            if (!nmod_poly_is_zero(R))
            {
                nmod_poly_pow(t, t, exp);
                nmod_poly_mul(poly, poly, t);
                max_exp = FLINT_MAX(exp, max_exp);
            }
        }

        v = nmod_poly_is_squarefree(poly);

        if (v == 1)
            result = (max_exp <= 1 && !nmod_poly_is_zero(poly));
        else
            result = (max_exp > 1 || nmod_poly_is_zero(poly));

        if (!result)
        {
            flint_printf("FAIL: %wu, %wd, %d\n", modulus, max_exp, v);
            nmod_poly_print(poly); flint_printf("\n");
            abort();
        }

        nmod_poly_clear(poly);
        nmod_poly_clear(t);
        nmod_poly_clear(Q);
        nmod_poly_clear(R);
    }

    FLINT_TEST_CLEANUP(state);
    
    flint_printf("PASS\n");
    return 0;
}
Exemple #4
0
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;
}