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

int main(int argc, char **argv)
{
	int myid, i, comm_size;
	float *a, b[3];
	

	MPI_Init(&argc, &argv); 

	MPI_Comm_rank(MPI_COMM_WORLD, &myid); 
	MPI_Comm_size(MPI_COMM_WORLD, &comm_size); 

	b[0] = myid * 1; b[1] = myid * 2; b[2] = myid * 3;
	
	if (myid == 0) {
		a = (float*) malloc(100 * sizeof(float));
	}

	MPI_Gather(b, 3, MPI_FLOAT, a, 3, MPI_FLOAT, 0, MPI_COMM_WORLD);
	
	
	/* wypisanie tablicy i zwolnienie pamieci w procesie 0 */
	if (myid == 0) {
		for(i = 0; i < comm_size * 3; i++)
				printf("a[%d] = %f\n", i, a[i]);
		free(a);
	}
	MPI_Finalize();

    return 0;
}