/* send.c
 * processor 0 sends an array to processor 1 
 * 
 */

#include <stdio.h>
#include "mpi.h"
#define NDIM 3

int main(int argc, char *argv[])
{
     int rank, value, size, errcode=1, src=0, dest=1, i, f[NDIM];
     MPI_Status status;
     FILE *fp;
     char fn[80];

     MPI_Init(&argc, &argv);
     MPI_Comm_rank( MPI_COMM_WORLD, &rank);
     MPI_Comm_size( MPI_COMM_WORLD, &size);
     if (size > 2) MPI_Abort(MPI_COMM_WORLD, errcode);

     /* initialize */
     if (rank == 0) {
          for (i=0; i<NDIM; i++) f[i] = i;
     } else {
          for (i=0; i<NDIM; i++) f[i] = 0;
     }
     sprintf(fn,"array%d.dat",rank);
     fp = fopen(fn,"w");

     fprintf(fp,"my rank = %d (BEFORE send/recv)\n",rank);
     for (i=0; i<NDIM; i++) fprintf(fp,"f[%d]=%d\n",i,f[i]);

     if (rank == src) 
          MPI_Send(f, NDIM, MPI_INT, dest, 0, MPI_COMM_WORLD);
     if (rank == dest) 
          MPI_Recv(f, NDIM, MPI_INT, src, 0, MPI_COMM_WORLD, &status);

     fprintf(fp,"my rank = %d (AFTER send/recv)\n",rank);
     for (i=0; i<NDIM; i++) fprintf(fp,"f[%d]=%d\n",i,f[i]);

     fclose(fp);

     MPI_Finalize( );
     return 0;
}