vector<int> mult_dims(1, 2);

explicit vector (size_type n, const value_type& val);

vector<int> mult_dims(1, 2);

std::vector<int> NO_mult_dims = {2};

std::vector<std::vector<int>> multi_dims{};

std::vector<int> my_vec = { 1, 2 };

std::vector<std::vector<int>> vec;   //vector of vector for matrix
vec.push_back({ 10,20,30 }); //first row
vec.push_back({ 11,22,33 });  // second row

for (auto x : vec)                  //printing matrix
{ std::cout << x[0] << " " << x[1] << " "<<x[2]<<std::endl; }

return 0;