Creating multidimensional array on the heap

Question

What is the right way to create a mutlidimensional array in C on the heap. Suppose I want an array with dimension 100x90x80
int arr[100][90][80];
would create it on the stack.
How can I create it on the heap so I can use it the same way (as if it was on the stack). Should i use malloc? In what way? (I can't cast the returned pointer without getting compile error). Or new?
How to correctly deallocate it?

Answer 1

So it is not possible in a more nice way?
It is quite long with the loops. Maybe flatenning the array would be a better way?

Answer 2

rudolph flash True, but imagine having a 3D or 4D array. Three nested loops only to allocate it.
How is it with performance/speed? Are flat arrays any faster or not?

Answer 3

~ swim ~
1D
v=vector<int>(8)
2D
v=vector<vector<int>>(8, vector<int>(8))
3D //three times 'vector'
v=vector<vector<vector<int>>>(8, vector<vector<int>>(8, vector<int>(8))) //6 times vector
In order to get nD vector, you have to write 'vector<' n*(n+1)/2 times.

Answer 4

~ swim ~ Thanks. So 1D could really be better (at least for writing the code). If using vectors with given size, it requires 'quadratic' length of code, doesn'it it
a=vector vector vector int (9, vector vector int (8, vector int(7)))
You have 3+2+1 times vector. This function grows quadratically :)