The Tor Browser / file diff

     1.1 --- /dev/null	Thu Jan 01 00:00:00 1970 +0000
     1.2 +++ b/security/nss/lib/freebl/mpi/utils/fact.c	Wed Dec 31 06:09:35 2014 +0100
     1.3 @@ -0,0 +1,82 @@
     1.4 +/*
     1.5 + * fact.c
     1.6 + *
     1.7 + * Compute factorial of input integer
     1.8 + *
     1.9 + * This Source Code Form is subject to the terms of the Mozilla Public
    1.10 + * License, v. 2.0. If a copy of the MPL was not distributed with this
    1.11 + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
    1.12 +
    1.13 +#include <stdio.h>
    1.14 +#include <stdlib.h>
    1.15 +#include <string.h>
    1.16 +
    1.17 +#include "mpi.h"
    1.18 +
    1.19 +mp_err mp_fact(mp_int *a, mp_int *b);
    1.20 +
    1.21 +int main(int argc, char *argv[])
    1.22 +{
    1.23 +  mp_int  a;
    1.24 +  mp_err  res;
    1.25 +
    1.26 +  if(argc < 2) {
    1.27 +    fprintf(stderr, "Usage: %s <number>\n", argv[0]);
    1.28 +    return 1;
    1.29 +  }
    1.30 +
    1.31 +  mp_init(&a);
    1.32 +  mp_read_radix(&a, argv[1], 10);
    1.33 +
    1.34 +  if((res = mp_fact(&a, &a)) != MP_OKAY) {
    1.35 +    fprintf(stderr, "%s: error: %s\n", argv[0],
    1.36 +	    mp_strerror(res));
    1.37 +    mp_clear(&a);
    1.38 +    return 1;
    1.39 +  }
    1.40 +
    1.41 +  {
    1.42 +    char  *buf;
    1.43 +    int    len;
    1.44 +
    1.45 +    len = mp_radix_size(&a, 10);
    1.46 +    buf = malloc(len);
    1.47 +    mp_todecimal(&a, buf);
    1.48 +
    1.49 +    puts(buf);
    1.50 +
    1.51 +    free(buf);
    1.52 +  }
    1.53 +
    1.54 +  mp_clear(&a);
    1.55 +  return 0;
    1.56 +}
    1.57 +
    1.58 +mp_err mp_fact(mp_int *a, mp_int *b)
    1.59 +{
    1.60 +  mp_int    ix, s;
    1.61 +  mp_err    res = MP_OKAY;
    1.62 +
    1.63 +  if(mp_cmp_z(a) < 0)
    1.64 +    return MP_UNDEF;
    1.65 +
    1.66 +  mp_init(&s);
    1.67 +  mp_add_d(&s, 1, &s);   /* s = 1  */
    1.68 +  mp_init(&ix);
    1.69 +  mp_add_d(&ix, 1, &ix); /* ix = 1 */
    1.70 +
    1.71 +  for(/*  */; mp_cmp(&ix, a) <= 0; mp_add_d(&ix, 1, &ix)) {
    1.72 +    if((res = mp_mul(&s, &ix, &s)) != MP_OKAY)
    1.73 +      break;
    1.74 +  }
    1.75 +
    1.76 +  mp_clear(&ix);
    1.77 +
    1.78 +  /* Copy out results if we got them */
    1.79 +  if(res == MP_OKAY)
    1.80 +    mp_copy(&s, b);
    1.81 +
    1.82 +  mp_clear(&s);
    1.83 +
    1.84 +  return res;
    1.85 +}