how to create a contiguous 2d array in c++?

Question

I want to create a function that returns a contiguous 2D array in C++.

It is not a problem to create the array using the command:

 int (*v)[cols] = n         


        

Answer 1

Since you're using C++ and not C, I would recommend to use one vector instead of messing around with new/delete.

You can define one contiguous block of memory like this:

std::vector my_matrix(rows*cols);

And now you access this vector in a 2d-array-like way with the formula i*n + j, with i being the row index, j the column index and n the length of a row:

my_matrix[i*n + j];

That's the same as accessing a 2d array with array[i][j]. But now you have the advantage of one contiguous block of memory, you don't need to bother about new/delete and you can easily share and return this vector object with functions.