int main int argc char argv int rank procNum MPI_Init argc argv MPI_Co

int main ( int argc, char *argv[] ) {
	int rank, procNum;
	MPI_Init(&argc, &argv);
	MPI_Comm_size(MPI_COMM_WORLD, &procNum);
	MPI_Comm_rank(MPI_COMM_WORLD, &rank);
	int startTime = MPI_Wtime();

	//matrix N*M, vector M;
	//(N - количество строк, M - количество столбцов)
	const int N = 8000, M = 8000; 
	const int buf_N = N/procNum;

	double* matrix = new double[N*M*sizeof(double)];
	double* vector = new double[N*sizeof(double)];
	double* buf_matr = new double[M*buf_N*sizeof(double)]; 
	double* res = new double[M*sizeof(double)];
	double* buf_res = new double[M*sizeof(double)];

	if (rank == 0)
		init(matrix, vector, N, M);

	//loop for best time estimate
	for (int i=0; i < 100; i++){
		MPI_Bcast(vector, M, MPI_DOUBLE, 0, MPI_COMM_WORLD);
		MPI_Scatter(matrix, M*buf_N, MPI_DOUBLE, buf_matr, M*buf_N, MPI_DOUBLE, 0, MPI_COMM_WORLD);
	
		buf_res = multiply_matrix(buf_matr, vector, buf_N, M);
	
		MPI_Gather(buf_res, buf_N, MPI_DOUBLE, res, buf_N, MPI_DOUBLE, 0, MPI_COMM_WORLD);
	}

	if (rank == 0){ 
		cout << "proc num: " << procNum << "; time: " << MPI_Wtime()-startTime << "\n";
	}

	delete[] matrix;
	delete[] vector;
	delete[] buf_matr;
	delete[] res;
	delete[] buf_res;

	MPI_Finalize();

	return 0;
}