Inserting elements in multidimensional Vector

Question

vector> sort_a;
vector v2;
vector v3;

for (int i=0; i<4; ++i) {
v2.push_back(i);

  for (int j=0; j<4; ++j) {
           


        

Answer 1

a vector> is not the best implementation for a multidimensional storage. The following implantation works for me.

template
class array_2d {
    std::size_t data;
    std::size_t col_max;
    std::size_t row_max;
    std::vector a;
public:
    array_2d(std::size_t col, std::size_t row) 
         : data(col*row), col_max(col), row_max(row), a(data)
    {}

    T& operator()(std::size_t col, std::size_t row) {
        assert(col_max > col && row_max > row)
        return a[col_max*col + row];
    }
};

use case:

array_2d a(2,2);
a(0,0) = 1;
cout << a(0,0) << endl;

This solution is similar to the one described here.