concatenateSubsets()

int Subsets::concatenateSubsets ( const Subset & s, const Subset & t, Subset & result )

static

Definition at line 163 of file comb.cpp.

{
  size_t p = s.size();
  size_t q = t.size();
  assert(p + q == result.size());
  size_t a = 0;
  size_t b = 0;
  size_t c = 0;
  size_t sign = 0;
  if (p == 0 && q == 0) return 1;
  for (;;)
    {
      if (a >= p)
        {
          while (b < q) result[c++] = t[b++];
          break;
        }
      else if (b >= q)
        {
          while (a < p) result[c++] = s[a++];
          break;
        }
      if (s[a] > t[b])
        {
          sign += p - a;
          result[c++] = t[b++];
        }
      else if (s[a] < t[b])
        {
          result[c++] = s[a++];
        }
      else
        return 0;
    }
  if ((sign % 2) == 0) return 1;
  return -1;
}

References p, result(), and s.

Referenced by TEST(), and Matrix::wedge_product().