Hello World Program of MPI + c

#include <stdio.h>#include <mpi.h>int main (int argc, char *argv[])//      int argc;//      char *argv[];{        int myid, numprocs, namelen;        char processor_name[MPI_MAX_PROCESSOR_NAME];        MPI_Init (&argc, &argv);        /* starts MPI */        MPI_Comm_rank (MPI_COMM_WORLD, &myid);  /* get current process id */        MPI_Comm_size (MPI_COMM_WORLD, &numprocs);      /* get number of processes */        MPI_Get_processor_name(processor_name,&namelen);        if(myid == 0) printf("number of processes: %d\n",numprocs);        printf( "%s: Hello world from process %d \n", processor_name, myid);        MPI_Finalize();        return 0;}

[root@c0109 zmpi]# mpicc hello.c -o hello[root@c0109 zmpi]# mpiexec -n 10 ./hellonumber of processes: 10c0109: Hello world from process 0 c0105: Hello world from process 1 c0106: Hello world from process 2 c0107: Hello world from process 4 c0102: Hello world from process 3 c0108: Hello world from process 5 c0110: Hello world from process 6 c0103: Hello world from process 7 c0104: Hello world from process 8 c0101: Hello world from process 9 [root@c0109 zmpi]#