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/* Exercise mpz_probab_prime_p.
Copyright 2002 Free Software Foundation, Inc.
This file is part of the GNU MP Library.
The GNU MP Library is free software; you can redistribute it and/or modify
it under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation; either version 3 of the License, or (at your
option) any later version.
The GNU MP Library is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
License for more details.
You should have received a copy of the GNU Lesser General Public License
along with the GNU MP Library. If not, see http://www.gnu.org/licenses/. */
#include <stdio.h>
#include <stdlib.h>
#include "gmp.h"
#include "gmp-impl.h"
#include "tests.h"
/* Enhancements:
- Test some big primes don't come back claimed to be composite.
- Test some big composites don't come back claimed to be certainly prime.
- Test some big composites with small factors are identified as certainly
composite. */
/* return 1 if prime, 0 if composite */
int
isprime (long n)
{
long i;
n = ABS(n);
if (n < 2)
return 0;
if (n == 2)
return 1;
if ((n & 1) == 0)
return 0;
for (i = 3; i < n; i++)
if ((n % i) == 0)
return 0;
return 1;
}
void
check_one (mpz_srcptr n, int want)
{
int got;
got = mpz_probab_prime_p (n, 25);
/* "definitely prime" is fine if we only wanted "probably prime" */
if (got == 2 && want == 1)
want = 2;
if (got != want)
{
printf ("mpz_probab_prime_p\n");
mpz_trace (" n ", n);
printf (" got =%d", got);
printf (" want=%d", want);
abort ();
}
}
void
check_pn (mpz_ptr n, int want)
{
check_one (n, want);
mpz_neg (n, n);
check_one (n, want);
}
/* expect certainty for small n */
void
check_small (void)
{
mpz_t n;
long i;
mpz_init (n);
for (i = 0; i < 300; i++)
{
mpz_set_si (n, i);
check_pn (n, isprime (i));
}
mpz_clear (n);
}
int
main (void)
{
tests_start ();
check_small ();
tests_end ();
exit (0);
}
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