added helloworld.c

helloworld.c

+#include <stdio.h>
+#include <mpi.h>
+int main(int argc, char *argv[])
+{
+int rank, size;
+MPI_Init(&argc, &argv); /* starts MPI */
+MPI_Comm_rank(MPI_COMM_WORLD, &rank); /* get current process id */
+MPI_Comm_size (MPI_COMM_WORLD, &size); /* get processor count*/
+if (rank == 0)
+printf( "Hello world from process %d of %d\n", rank, size );
+else
+printf( "Hello world from process %d of %d\n", rank, size );
+sleep(1);
+MPI_Finalize();
+return 0;
+}