#include <stdio.h>
#include <string.h>
#include "mpi.h"
int main(int argc, char** argv) {
    int my_rank, nproc,  src, dst, tag = 50;
    char msg[100];
    MPI_Status status;
    MPI_Init(&argc, &argv);
    MPI_Comm_rank(MPI_COMM_WORLD, &my_rank);
    MPI_Comm_size(MPI_COMM_WORLD, &nproc);
    if (my_rank != 0) {
      sprintf(msg, "Greetings from process %d!",
              my_rank);
      dst = 0;
      MPI_Send(msg,strlen(msg)+1,MPI_CHAR,dst,tag,MPI_COMM_WORLD);
    } else {
      for (src = 1; src < nproc; src++) {
        MPI_Recv(msg,100,MPI_CHAR,src,tag,MPI_COMM_WORLD,&status);
        printf("%s\n", msg);
      }
    }
    MPI_Finalize();
    return 0;
}