116 lines
2.3 KiB
C
116 lines
2.3 KiB
C
/* 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 2.1 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; see the file COPYING.LIB. If not, write to
|
|
the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
|
|
MA 02110-1301, USA. */
|
|
|
|
#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);
|
|
}
|