MPI send revc pointers - c++

Question

I have a pointer to a list of pointers (each pointer of the list point to a row)
I need to "scatter" the list of pointers so that each processor has a certain number of rows.
I make an example to say how I want to assign the pointers.
If the list is composed by 5 pointers and there are 2 processors, I want that processor0 has pointers 4 0 1 2 3 and processor1 has 2 3 4 0 (this mean that each processor has the last pointer of the previous processor and the first pointer of the following processor)
This is part of the code:
int **vptr = NULL;
if(rank==0){
vptr = m.ptr();
}
//this definition comes from one of my class methods
then I have this part of code that decide how to assign the rows to each process (assuming at the outset that each processor has only the rows that others do not have)
int *elem;
elem = new int[p]; //number of rows for process
int *disp;
disp = new int[p]; //index first row of the process
int split = N / p;
int extra = N % p;
for(unsigned i = 0; i < extra; i++){
elem[i] = split + 1;
}
for(unsigned i = extra; i < p; i++){
elem[i] = split;
}
disp[0] = 0;
for(unsigned i = 1; i < p; i++){
disp[i] = disp[i-1] + elem[i-1];
}
int local_n = elem[rank]; //number of rows for this process
int local_f = disp[rank]; //index first row for this process
int *local_v;
local_v = new int[local_n + 2]; //+2 because now I consider that I also need the row above and the row below
here I need to use MPI_Send and MPI_Recv, I suppose I am making an erroror with the pointers
if(rank==0){
for(unsigned j = 0; j < local_n + 2; j++){
local_v[j] = *vptr[j];
}
for(unsigned i = 1; i < p; i++){
MPI_Send(&vptr[disp[i]-1], elem[i] + 2, MPI_INT, i, 1, MPI_COMM_WORLD);
}
}else{
MPI_Recv(&local_v[0], local_n + 2, MPI_INT, 0, 1, MPI_COMM_WORLD, MPI_STATUS_IGNORE);
}

Answer 1

Comment converted to answer in the pursuit of vainglorious reputation ... (and the slightly more noble pursuit of providing an acceptable answer for future generations)
I'm not sure I entirely understand your code but there is no point sending pointers from one process to another. Pointers point to locations in the local address space of a process and can not be expected to point to a specific location in the local address space of another process. Indeed, they cannot be expected to continue to point to any location in the local address space of another process