/* This is a simple MPI program. It uses the six basic MPI functions to make */
/* a complete MPI program. */
/* Classroom demonstration */
/* Xianong Meng UTPA-CS    */
/* modified sep-5-2000     */

#include <stddef.h>
#include <stdlib.h>
#include "mpi.h"
main(int argc, char **argv )
{
	char message[20];
	int i,rank, id, size, type=99;
	MPI_Status status;

	MPI_Init(&argc, &argv);              /* start MPI */
	MPI_Comm_size(MPI_COMM_WORLD,&size); /* get communicator size */
	MPI_Comm_rank(MPI_COMM_WORLD, &rank);/* get my own rank */
	if(rank == 0) {                      /* parent process  */
	   strcpy(message, "Hello, world");
	   for (i=1; i<size; i++) 
	   MPI_Send(message, strlen(message)+1, MPI_CHAR, i, 
               type, MPI_COMM_WORLD);        /* send message to every one */
	   for (i=1; i<size; i++)            /* try to receive from every */
					     /* one */
	     {
	       MPI_Recv(&id, 1, MPI_INT, i, 
			type, MPI_COMM_WORLD, &status);
	       printf("Id from node %d is %d\n",i,id);
	     }
	} 
  	else                                /* child process */
	  {
	    MPI_Recv(message, 20, MPI_CHAR, 0,
		     type, MPI_COMM_WORLD, &status);
	    MPI_Send(&rank,1,MPI_INT,0,type,MPI_COMM_WORLD);

	  }
      	MPI_Finalize();                     /* clean up MPI */
}