#include <stdio.h>
#include "mpi.h"

main(int argc, char **argv ) {
	char message[256];
	int i,rank, size, tag=99;
	char machine_name[256];
	MPI_Status status;

	MPI_Init(&argc, &argv);
	MPI_Comm_size(MPI_COMM_WORLD, &size);
	MPI_Comm_rank(MPI_COMM_WORLD, &rank);

	gethostname(machine_name, 255);

	if(rank == 0) {
		printf ("Hello world from master process %d running on %s\n",rank,machine_name);
		for (i = 1; i < size; i++) {
			MPI_Recv(message, 256, MPI_CHAR, i, tag, MPI_COMM_WORLD, &status);
			printf("Message from process = %d : %s\n", i, message);
		}
	} else {
		sprintf(message, "Hello world from process %d running on %s",rank,machine_name);
		MPI_Send(message, 256, MPI_CHAR, 0, tag, MPI_COMM_WORLD);
	}

	MPI_Finalize();
	return(0);
}