//HelloWorldMPI, from John Urbanic psc slides

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

int main(int argc, char **argv)
{
	int rank, size;
	
    MPI_Init(&argc, &argv);
    MPI_Comm_rank(MPI_COMM_WORLD, &rank); // Who am I?
	MPI_Comm_size(MPI_COMM_WORLD, &size); // how many in all?
    printf("Hello world. I am %d of %d\n", rank, size);
    MPI_Finalize();
    return 0;
}

/*
MPICH version on the workstations:
mpicc.mpich -o helloWorldMpi helloWorldMpi.c

mpirun -np 4 -all-local helloWorldMPI   (we're using only one workstation for now)


(enter password 3 times)

Hello world. I am 0 of 4
Hello world. I am 2 of 4
Hello world. I am 1 of 4
Hello world. I am 3 of 4


CRAY SV1:

cc helloWorld2.c 

mpirun -np 4 a.out
Hello world. I am 0 of 4
Hello world. I am 1 of 4
Hello world. I am 2 of 4
Hello world. I am 3 of 4

mpirun -np 16 a.out
Hello world. I am 0 of 16
Hello world. I am 3 of 16
Hello world. I am 4 of 16
Hello world. I am 5 of 16
Hello world. I am 6 of 16
Hello world. I am 8 of 16
Hello world. I am 9 of 16
Hello world. I am 1 of 16
Hello world. I am 2 of 16
Hello world. I am 7 of 16
Hello world. I am 10 of 16
Hello world. I am 14 of 16
Hello world. I am 15 of 16
Hello world. I am 11 of 16
Hello world. I am 12 of 16
Hello world. I am 13 of 16


*/