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

int main(int argc, char* argv[]){
	int  my_rank,RecRank; /* rank of process */
	int  p;       /* number of processes */
	int source;   /* rank of sender */
	int dest;     /* rank of receiver */
	int tag0=0;    /* tag for messages */
	int tag1=1;
	//char message[100];        /* storage for message */
	MPI_Status status ;   /* return status for receive */
	//MPI_Comm newComm;
	/* 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);
	//MPI_Cart_create(MPI_COMM_WORLD,1,(int*)p,(int*)1,1,&new_comm);

	if(my_rank==0){
		source=p-1;
	}else{
		source=my_rank-1;
	}

	if(my_rank== p-1){
		dest=0;
	}else{
		dest=my_rank+1;
	}

	MPI_Send(&my_rank, 1, MPI_INT, dest, tag0, MPI_COMM_WORLD);
	while (1){
		MPI_Recv(&RecRank, 1, MPI_INT, source, MPI_ANY_TAG, MPI_COMM_WORLD, &status);
		if(status.MPI_TAG==0){
			if(RecRank>my_rank){
				MPI_Send(&RecRank, 1, MPI_INT, dest, tag0, MPI_COMM_WORLD);
			}else if(RecRank==my_rank){
				MPI_Send(&RecRank, 1, MPI_INT, dest, tag1, MPI_COMM_WORLD);
			}

		}else{
			if(RecRank!=my_rank){
				MPI_Send(&RecRank, 1, MPI_INT, dest, tag1, MPI_COMM_WORLD);
			}
			break;
		}
	}
	printf("liderul: %d\n",RecRank);

	/* shut down MPI */
	MPI_Finalize();

	return 0;
}