/*
"Hello World" example for "p" number of processors. 
  Initially, all processors have status "I am alone!". 
  Each sends out a "Hello World" to all others. 
  Upon receiving the messages, each processors'sstatus changes 
  to what is received.
*/
#include "mpi.h"
#include <stdio.h>
int main(intargc, char** argv)
{
   int MyProc, size, tag = 0;
   int send_proc= 0, recv_proc= 0;
   char msg[12]="Hello World";
   char msg_recpt[12]="I am alone!";
   MPI_Status status;

   MPI_Init(&argc, &argv);
   MPI_Comm_rank(MPI_COMM_WORLD, &MyProc);
   MPI_Comm_size(MPI_COMM_WORLD, &size);

   printf("Process# %d started \n", MyProc);
   printf("Proc#%d: %s \n", MyProc, msg_recpt) ;
   MPI_Barrier(MPI_COMM_WORLD);
for (send_proc= 0; send_proc< size; send_proc++)
{
  if (send_proc!= MyProc)
  {
   printf("Proc#%d sending message to Proc #%d: %s \n", MyProc, send_proc, msg);
   MPI_Send(&msg, 12, MPI_CHAR, send_proc, tag, MPI_COMM_WORLD);
  }
}
for (recv_proc= 0; recv_proc< size; recv_proc++)
{
  if (recv_proc!= MyProc)
  {
   MPI_Recv(&msg_recpt, 12, MPI_CHAR, recv_proc, tag, MPI_COMM_WORLD, &status);
   printf("Proc#%d received message from Proc #%d: %s \n", MyProc, recv_proc, msg_recpt);
   }
  }
  //MPI_Barrier(MPI_COMM_WORLD);
  MPI_Finalize();
}