/*
 ============================================================================
 Name        : Laboratorul4.c
 Author      : Author
 Version     :
 Copyright   : Your copyright notice
 Description : Hello MPI World in C
 ============================================================================
 */
#include <stdio.h>
#include <string.h>
#include "mpi.h"

int main(int argc, char* argv[]){
	int  my_rank; /* rank of process */
	int  p;       /* number of processes */
	int source;   /* rank of sender */
	int dest;     /* rank of receiver */
	int tag=0;    /* tag for messages */
	char message[100]; /* storage for message */

	int d = 3;
	int k;
	int source_virtual;
	int masca = (1<<d)-1;

	source = 8;
	//dest = 7;

	MPI_Status status ;   /* return status for receive */

	/* start up MPI */

	MPI_Init(&argc, &argv);

	/* find out process rank */
	MPI_Comm_rank(MPI_COMM_WORLD, &my_rank);

	/* find out number of processes */
	MPI_Comm_size(MPI_COMM_WORLD, &p);

	int id_virtual = source ^ my_rank;



	for(k = d - 1; k >= 0; k--)
	{
		masca = masca ^ 1 << k;
		if((id_virtual & masca) == 0)
		{
			if((id_virtual & 1<<k) == 0)
			{
				dest = id_virtual ^ 1<<k ;
				dest = dest ^ source;
				printf("Mesaj\n");
				sprintf(message, "Hello");
				MPI_Send(message, strlen(message)+1, MPI_CHAR,
						   dest, tag, MPI_COMM_WORLD);
			}
			else
			{
				source_virtual = id_virtual ^ 1<<k;
				source_virtual = source_virtual ^ source;
				MPI_Recv(message, 100, MPI_CHAR, source_virtual , tag,
							      MPI_COMM_WORLD, &status);
				printf("%d sent %s to %d\n",source_virtual, message, my_rank);
			}
		}
		MPI_Barrier(MPI_COMM_WORLD);
	}
	/* shut down MPI */
	MPI_Finalize();


	return 0;
}