116 lines
2.4 KiB
C
116 lines
2.4 KiB
C
/* Exercise mpz_probab_prime_p.
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Copyright 2002 Free Software Foundation, Inc.
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This file is part of the GNU MP Library.
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The GNU MP Library is free software; you can redistribute it and/or modify
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it under the terms of the GNU Lesser General Public License as published by
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the Free Software Foundation; either version 2.1 of the License, or (at your
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option) any later version.
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The GNU MP Library is distributed in the hope that it will be useful, but
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WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
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or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
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License for more details.
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You should have received a copy of the GNU Lesser General Public License
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along with the GNU MP Library; see the file COPYING.LIB. If not, write to
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the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
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MA 02110-1301, USA. */
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#include <stdio.h>
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#include <stdlib.h>
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#include "gmp.h"
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#include "gmp-impl.h"
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#include "tests.h"
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/* Enhancements:
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- Test some big primes don't come back claimed to be composite.
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- Test some big composites don't come back claimed to be certainly prime.
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- Test some big composites with small factors are identified as certainly
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composite. */
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/* return 1 if prime, 0 if composite */
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int
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isprime (long n)
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{
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long i;
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n = ABS(n);
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if (n < 2)
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return 0;
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if (n == 2)
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return 1;
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if ((n & 1) == 0)
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return 0;
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for (i = 3; i < n; i++)
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if ((n % i) == 0)
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return 0;
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return 1;
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}
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void
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check_one (mpz_srcptr n, int want)
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{
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int got;
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got = mpz_probab_prime_p (n, 25);
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/* "definitely prime" is fine if we only wanted "probably prime" */
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if (got == 2 && want == 1)
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want = 2;
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if (got != want)
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{
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printf ("mpz_probab_prime_p\n");
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mpz_trace (" n ", n);
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printf (" got =%d", got);
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printf (" want=%d", want);
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abort ();
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}
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}
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void
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check_pn (mpz_ptr n, int want)
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{
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check_one (n, want);
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mpz_neg (n, n);
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check_one (n, want);
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}
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/* expect certainty for small n */
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void
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check_small (void)
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{
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mpz_t n;
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long i;
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mpz_init (n);
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for (i = 0; i < 300; i++)
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{
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mpz_set_si (n, i);
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check_pn (n, isprime (i));
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}
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mpz_clear (n);
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}
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int
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main (void)
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{
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tests_start ();
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check_small ();
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tests_end ();
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exit (0);
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}
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