c++ sort keeping track of indices

Question

do you have some efficient routine for returning array with indices for sorted elements in a array? I think that some convenient way exists using stl vector. Do you have alr

Answer 1

You could try something like this:

template
class index_sorter {
  public:
    compare(C const& c) : c(c) {}
    bool operator()(std::size_t const& lhs, std::size_t const& rhs) const {
      return c[lhs] < c[rhs];
    }
  private:
    C const& c;
};

std::sort(index_vector.begin(), index_vector.end(), index_sorter(vector));