How to dynamically allocate a contiguous block of memory for a 2D array

Question

If I allocate a 2D array like this int a[N][N]; it will allocate a contiguous block of memory.

But if I try to do it dynamically like this :

<

Answer 1

You can typedef your array (for less headake) and then do something like that:

#include 
#define N 10
typedef int A[N][N];
int main () {
  A a; // on the stack
  a[0][0]=1;
  A *b=(A*)malloc (sizeof(A)); // on the heap
  (*b)[0][0]=1;
}