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

int main(int argc, char *argv[])
{
	int rank, size;

	MPI_Init(&argc, &argv);
	
	MPI_Comm_rank(MPI_COMM_WORLD, &rank);
	MPI_Comm_size(MPI_COMM_WORLD, &size);

	int n = 10;
	int a[10] = {1,2,3,4,5,6,7,8,9,10};

	int b[n];
	int myN;

	int k[10];

	if (rank == 0)
	{
		int br = 0;
	
		for (int i = 0; i < size; i++)
		{
			k[i] = i < n/size ? n/size + 1 : n/size;

			MPI_Send(k + i, 1, MPI_INT, i, 100, MPI_COMM_WORLD);
			MPI_Send(a + br, k[i], MPI_INT, i, 200, MPI_COMM_WORLD);

			br += k[i];	
		}	
	}

	MPI_Recv(&myN, 1, MPI_INT, 0, 100, MPI_COMM_WORLD, NULL);
	MPI_Recv(b, myN, MPI_INT, 0, 200, MPI_COMM_WORLD, NULL);
	
	int sum = 0, ukupno = 0;

	for (int i = 0; i < myN; i++)
	{
		sum += b[i];
	}

	MPI_Reduce(&sum, &ukupno, 1, MPI_INT, MPI_SUM, 0, MPI_COMM_WORLD);

	if (rank == 0)
	{
		printf("sum: %d\n", ukupno);
	}

	MPI_Finalize();
	return 0;
}