moja przyśpieszona symulacja #talerz

void sortrows(std::vector<std::vector<double>>& matrix, vector<int> &columns) {
        int i=columns.size()-1;
        std::sort(matrix.begin(),
            matrix.end(),
            [columns, i](const std::vector<double>& lhs, const std::vector<double>& rhs) {
            int col = columns[i];
            if (lhs[col] == rhs[col])
            {
                if (i>0)
                {
                    int second_col = columns[i - 1];
                    if (lhs[second_col] == rhs[second_col])
                    {
                        if (i>1)
                        {
                            int third_col = columns[i - 2];
                            return lhs[third_col] < rhs[third_col];
                        }
                    }
                    return lhs[second_col] < rhs[second_col];
                }
            }
            return lhs[col] < rhs[col];
        });
}