decode()

void Subsets::decode	(	size_t	val,
		Subset &	result )

Definition at line 96 of file comb.cpp.

{
  size_t tmp = val;
  size_t subsetSize = result.size();
  assert(val <= binom(mNumElements, subsetSize));
 
  size_t len = mNumElements;
 
  for (size_t i = subsetSize; i > 0; i--)
    {
      size_t bit;
      size_t bot = 0;
      while (bit = len % 2, len >>= 1)
        {
          if (binom(bot + len, i) <= tmp)
            {
              bot += len;
              len += bit;
            }
        }
      result[i - 1] = bot;
      tmp -= binom(bot, i);
      len = bot + 1;
    }
 
  assert(isValid(result));
}

References binom(), isValid(), mNumElements, and result().

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