double x_in[1024];/* buffer for random numbers */
int main(int argc,char** argv)
{
.....

MPI_Init(&argc,&argv);
MPI_Comm_size(MPI_COMM_WORLD,&numtasks);
MPI_Comm_rank(MPI_COMM_WORLD,&rank);
if (rank == 0 && numtasks != 5) {
   printf("Number of tasks = %d\n",numtasks);
   printf("Only need 5 tasks - extra will be ignored...\n");
   }

MPI_Barrier(MPI_COMM_WORLD);

/******** Thread 0 ************************************/
if (rank == 0) {
 
   printf("task %d has started...\n", rank);
 
   dest = 1;

      /* send message to worker - message tag set to 1.  */
      /* If return code indicates error quit */

   rc = MPI_Send(x_in, 1, MPI_DOUBLE, dest, tag, MPI_COMM_WORLD);
   if (rc != MPI_SUCCESS) {
       printf("Send error in task 0!\n");
       MPI_Abort(MPI_COMM_WORLD, rc);
       exit(1);}
}
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I am waiting for your advice.

Thanks,

Zahra