/* bcast.c
 *
 * simple MPI_Bcast example
 * read in an integer from a file (para.dat) and broadcast it to all processes
 *
 */

#include <stdio.h>
#include "mpi.h"
#define ROOT 0
int main(int argc, char *argv[])
{
     int size, rank, x=0;
     MPI_Init(&argc, &argv);
     MPI_Comm_size(MPI_COMM_WORLD, &size);
     MPI_Comm_rank(MPI_COMM_WORLD, &rank);
     if (rank == ROOT) {
          FILE *fp = fopen("para.dat","r");
          fscanf(fp,"%d",&x); fclose(fp);
     }
     printf("(before) my rank = %d, x = %d\n", rank, x);
     MPI_Bcast(&x, 1, MPI_INT, ROOT, MPI_COMM_WORLD);
     printf("(after) my rank = %d, x = %d\n", rank, x);
     MPI_Finalize();
     return 0;
}