dynamic array as global variables

well i wish to ennounce two global variables to use after in a function.
One variable i define as an unidimensional vector. I did it very well, i
think so, the variable is called x[].
But i wish to define a new global variable, as bidimensional dynamic array,
is called a[][]. But i don't know how to define this dynamic array a[][] as
global variable.

I knwo how to define dynamica array(unidimensional or bidimensional) inside
the main program or inside any function, but as a global variable?

It is important to remark that i have defined in my program three or more
functions whose one of incoming variables is a bidimeniosnal dynamic
array.

Next i post a part of program


Program :
cpp code

using namespace std;
float a[16][16];
//in this part i wish define the bidimensional dynamic array


//i'm defining unidimensional dynamic array x
const N=1000;
float* x = new float[N];
//first function using dynamic array x[]

float suma3(float x[])
{
int j; float s=0.0;
for (j=1;j<16;j++)
s=s+x[j];
return(s);
}
//second function i wish , for example here, usin a[][] as bidimensional
dynamic array. how to do?
float suma1(int i, float x[], float a[][16])
{
int l;
float s=0;
for (l=1;l<i;l++)
{
s=s+a[i][l]*x[l];
}
return(s);
}///fin suma 1

they can be defined before headers, before using namespace, and it's the same
for all variables.
Something you might try is:

And it is before your loop. you can't put code out side of a function like that.