#include <mpi.h> 
#include <stdio.h> 
#include <stdlib.h> 
#define SIZE 4 

void main(int argc, char *argv[]) 
{ 
	int numtasks, rank, source=0, dest, tag=1, i; 
	float a[SIZE][SIZE] = 
	  {1.0, 2.0, 3.0, 4.0, 
	   5.0, 6.0, 7.0, 8.0, 
	   9.0, 10.0, 11.0, 12.0, 
	   13.0, 14.0, 15.0, 16.0}; 
	float b[SIZE]; 
	MPI_Status stat; 
	MPI_Datatype rowtype; 
	MPI_Init(&argc,&argv); 
	MPI_Comm_rank(MPI_COMM_WORLD, &rank); 
	MPI_Comm_size(MPI_COMM_WORLD, &numtasks); 
	MPI_Type_contiguous(SIZE, MPI_FLOAT, &rowtype); 
	MPI_Type_commit(&rowtype); 
	
	if (numtasks == SIZE) 
	{ 
		if (rank == 0) 
		{ 
			for (i=0; i < numtasks; i++) 
			MPI_Send(&a[i][0], 1, rowtype, i, tag, MPI_COMM_WORLD); 
		} 

		MPI_Recv(b, SIZE, MPI_FLOAT, source, tag, MPI_COMM_WORLD, &stat); 
		printf("rank= %d  b= %3.1f %3.1f %3.1f %3.1f\n", rank,b[0],b[1],b[2],b[3]); 
	} 
	else 
	  printf("Must specify %d processors. Terminating.\n",SIZE); 

	MPI_Finalize(); 
}