#include "mpi.h"
#include <stdio.h>
#include <stdlib.h>
#define NR 4
#define INF  999

int main(int argc, char **argv) {

	MPI_Init(&argc, &argv);
	int rank, numtasks;
	int masterGraph[NR][NR] = {{0}};
	MPI_Status stat;
	MPI_Comm_rank(MPI_COMM_WORLD, &rank);
	MPI_Comm_size(MPI_COMM_WORLD, &numtasks);

	int matrixGraph[NR][NR] = {
		{ 0, 5, 15, 3 },
		{ INF, 0, 6, INF },
		{ INF, INF, 0, 9 },
		{ 1, INF, INF, 0 },
	};
	//MPI_Bcast(matrixGraph, NR*NR, MPI_INT, 0, MPI_COMM_WORLD);

	if (rank == 0) {
		for (int k = 0; k < NR; k++) {
			for (int j = 0; j < NR; j++) {
				if (matrixGraph[0][k] + matrixGraph[k][j] < matrixGraph[0][j]) {
					matrixGraph[0][j] = matrixGraph[0][k] + matrixGraph[k][j];
				}
			}
		}
		for (int i = 0; i < NR; i++) {
			masterGraph[0][i] = matrixGraph[0][i];
			if (i != 0)
				MPI_Send(&matrixGraph, NR*NR, MPI_INT, i, 1, MPI_COMM_WORLD);
		}
		printf("\n");
	}
	if (rank != 0) {
		MPI_Recv(matrixGraph, NR*NR, MPI_INT, 0, 1, MPI_COMM_WORLD, &stat);
		for (int k = 0; k < NR; k++) {
			for (int j = 0; j < NR; j++) {
				if (matrixGraph[rank][k] + matrixGraph[k][j] < matrixGraph[rank][j]) {
					matrixGraph[rank][j] = matrixGraph[rank][k] + matrixGraph[k][j];
				}
			}
		}
		MPI_Send(&matrixGraph[rank], NR, MPI_INT, 0, 1, MPI_COMM_WORLD);
		//MPI_Alltoall(&matrixGraph, NR*NR, MPI_INT, 0 , NR*NR, MPI_INT, MPI_COMM_WORLD);
	}
	if (rank == 0) {

		for (int p = 1; p < numtasks; p++) {
			MPI_Recv(matrixGraph[p], NR, MPI_INT, p, 1, MPI_COMM_WORLD, &stat);
			for (int j = p; j < NR; j++) {
				for (int k = 0; k < NR; k++) {
					masterGraph[j][k] = matrixGraph[j][k];
				}
			}
		}
		for (int i = 0; i < NR; i++) {
			for (int j = 0; j < NR; j++) {
				if (masterGraph[i][j] == 999)
					printf("- ");
				else
					printf("%d ", masterGraph[i][j]);

			}
			printf("\n");
		}
	}
	MPI_Finalize();
}