示例#1
0
/*
 * Degree of variable x in b
 * - return largest d such that x^d occurs in b
 * - return 0 if x does not occur in b
 */
uint32_t arith_buffer_var_degree(arith_buffer_t *b, int32_t x) {
  mlist_t *p;
  uint32_t d, e;

  d = 0;
  p = b->list;
  while (p->next != NULL) {
    assert(p->prod != end_pp);
    if (q_is_nonzero(&p->coeff)) {
      e = pprod_var_degree(p->prod, x);
      if (e > d) {
        d = e;
      }
    }
    p = p->next;
  }

  return d;
}
示例#2
0
int main() {
  pprod_t *p1, *p2;
  uint32_t i, j;
  int32_t cmp;

  p[0] = empty_pp;
  p[1] = var_pp(0);
  p[2] = var_pp(1);
  p[3] = var_pp(0x3fffffff);

  init_pp_buffer(&buffer, 0);
  p[4] = pp_buffer_getprod(&buffer);  // empty

  pp_buffer_reset(&buffer);
  pp_buffer_mul_var(&buffer, 0);
  p[5] = pp_buffer_getprod(&buffer); // x_0

  pp_buffer_reset(&buffer);
  pp_buffer_mul_var(&buffer, 0);
  pp_buffer_mul_var(&buffer, 1);
  pp_buffer_mul_var(&buffer, 0);
  p[6] = pp_buffer_getprod(&buffer);  // x_0^2 x_1

  pp_buffer_reset(&buffer);
  pp_buffer_mul_varexp(&buffer, 1, 2);
  pp_buffer_mul_varexp(&buffer, 4, 3);
  p[7] = pp_buffer_getprod(&buffer);  // x_1^2 x_4^3

  pp_buffer_set_varexp(&buffer, 3, 2);
  pp_buffer_mul_varexp(&buffer, 1, 4);
  p[8] = pp_buffer_getprod(&buffer);   // x_3^2 x_1^4

  pp_buffer_set_pprod(&buffer, p[7]);
  pp_buffer_mul_pprod(&buffer, p[1]);
  pp_buffer_mul_pprod(&buffer, p[8]);
  p[9] = pp_buffer_getprod(&buffer);

  for (i=0; i<NUM_PRODS; i++) {
    printf("p[%"PRIu32"] =  ", i);
    print_pprod(stdout, p[i]);
    printf(" total degree = %"PRIu32"\n", pprod_degree(p[i]));
    for (j=0; j<5; j++) {
      printf(" degree of x_%"PRIu32" = %"PRIu32"\n", j, pprod_var_degree(p[i], j));
    }
    printf("----\n");
  }
  printf("\n");

  for (i=0; i<NUM_PRODS; i++) {
    p1 = p[i];
    for (j=0; j<NUM_PRODS; j++) {
      p2 = p[j];
      printf("p1: ");
      print_pprod0(stdout, p1);
      printf("p2: ");
      print_pprod0(stdout, p2);
      if (pprod_equal(p1, p2)) {
	printf("equal products\n");
      }
      if (pprod_divides(p1, p2)) {
	printf("p1 divides p2\n");
      }
      if (pprod_divisor(&buffer, p1, p2)) {
	printf("p2/p1: ");
	print_pp_buffer0(stdout, &buffer);
      }
      if (pprod_divides(p2, p1)) {
	printf("p2 divides p1\n");
      }
      if (pprod_divisor(&buffer, p2, p1)) {
	printf("p1/p2: ");
	print_pp_buffer0(stdout, &buffer);
      }
      cmp = pprod_lex_cmp(p1, p2);
      if (cmp < 0) {
	printf("p1 < p2 in lex order\n");
      } else if (cmp > 0) {
	printf("p1 > p2 in lex order\n");
      } else {
	printf("p1 = p2 in lex order\n");
      }
      if (pprod_precedes(p1, p2)) {
	printf("p1 < p2 in deglex ordering\n");
      }
      if (pprod_precedes(p2, p1)) {
	printf("p2 < p1 in deglex ordering\n");
      }
      printf("----\n");
    }
  }


  for (i=0; i<10; i++) {
    free_pprod(p[i]);
  }

  delete_pp_buffer(&buffer);

  return 0;
}