bn_mp_bell.c

#include <tommath.h>
#ifdef BN_MP_BELL_C
int mp_bell(unsigned long n, mp_int *c)
{
   unsigned long i = 0;
   mp_int s, temp;
   int e;
   if ((e = mp_init_multi(&s, &temp, NULL)) != MP_OKAY) {
      return e;
   }
   while (i++ <= n) {
      if ((e = mp_stirling2(n, i, &temp)) != MP_OKAY) {
         return e;
      }
      if ((e = mp_add(&s, &temp, &s)) != MP_OKAY) {
         return e;
      }
   }
   mp_exch(&s, c);
   mp_clear_multi(&s, &temp, NULL);
   return MP_OKAY;
}
#endif