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

int main(int argc, char *argv[])
     /*
 Mon premier programme en MPI C

 sur machine DIGITAL/Compaq  (alpha)
 compilation 
 cxx -o mpifileC mpifileC.c -lmpi 
 execution 
 dmpirun -np 2 mpifile

 sur la grappe de PC BioIMAGe
 gcc -o mpifileC mpifileC.c -lmpich ???
 
     */
{
  int rank, size;
  MPI_Status status;
  char SendMsg[]="Hello from processor 0";
  char RecvMsg[23];
  int root;
  int tag;
  int rankdest;

  int i;

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

  /* envoi du message */
  root = 0;
  if(rank==root)
    for(i=1;i<size;i++){
      tag=i;
      rankdest=i;
      MPI_Send(SendMsg,23,MPI_CHAR,rankdest,tag,MPI_COMM_WORLD);
    }
  /* reception du message */
  if(rank!=root) {
    tag = rank;
    MPI_Recv(RecvMsg,23,MPI_CHAR,root,tag,MPI_COMM_WORLD,&status);
    printf(" je suis le processeur %d, j'ai recu le message : %s \n",rank,RecvMsg);
  }
  MPI_Finalize();
}