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

void clearMyB(int[]);

void clearMyB(int MyB[])
{
	int i;
	for (i = 0; i < 5; i ++)
	{
		MyB[i] = 0;
	}
}

main( int argc, char** argv)
{
	int	MyPE,			//My logical process number
		NumPE,			//Number of processes
		i;				//loop index variable

	int	MyA[5],		//My portion of A
		MyB[5],		//My portion of B
		Recvcount1[4] = {1, 1, 1, 0},
		Recvcount2[4] = {1, 1, 1, 1},
		Recvcount3[4] = {1, 0, 3, 1},
		Recvcount4[4] = {1, 2, 0, 2};

	MPI_Init(&argc, &argv);
	MPI_Comm_rank(MPI_COMM_WORLD, &MyPE);
	MPI_Comm_size(MPI_COMM_WORLD, &NumPE);

	//Each proc fill their only array
	for (i = 0; i < 5; i ++)
	{
		MyA[i] = (MyPE + 1) * (i + 10);
		MyB[i] = 0;
	}
	printf("PE %d: MyA is - ", MyPE);
	for (i = 0; i < 5; i ++)
	{
		printf("%d ", MyA[i]);
	}
	printf("\n");

	///////////////////////////////////////////////////////////
	MPI_Reduce_scatter(MyA, MyB, Recvcount1, MPI_INT, MPI_SUM, MPI_COMM_WORLD);
	MPI_Barrier(MPI_COMM_WORLD);
	if (MyPE == 0)
		printf("Recvcount = {1, 1, 1, 0}\n");
	printf("PE %d: MyB is - ", MyPE);
	for (i = 0; i < 5; i ++)
	{
		printf("%d ", MyB[i]);
	}
	printf("\n");

	///////////////////////////////////////////////////////////
	MPI_Reduce_scatter(MyA, MyB, Recvcount2, MPI_INT, MPI_SUM, MPI_COMM_WORLD);
	MPI_Barrier(MPI_COMM_WORLD);
	if (MyPE == 0)
		printf("Recvcount = {1, 1, 1, 1}\n");
	printf("PE %d: MyB is - ", MyPE);
	for (i = 0; i < 5; i ++)
	{
		printf("%d ", MyB[i]);
	}
	printf("\n");
	clearMyB(MyB);

	///////////////////////////////////////////////////////////
	MPI_Reduce_scatter(MyA, MyB, Recvcount3, MPI_INT, MPI_SUM, MPI_COMM_WORLD);
	MPI_Barrier(MPI_COMM_WORLD);
	if (MyPE == 0)
		printf("Recvcount = {1, 0, 3, 1}\n");
	printf("PE %d: MyB is - ", MyPE);
	for (i = 0; i < 5; i ++)
	{
		printf("%d ", MyB[i]);
	}
	printf("\n");
	clearMyB(MyB);

	///////////////////////////////////////////////////////////
	MPI_Reduce_scatter(MyA, MyB, Recvcount4, MPI_INT, MPI_SUM, MPI_COMM_WORLD);
	MPI_Barrier(MPI_COMM_WORLD);
	if (MyPE == 0)
		printf("Recvcount = {1, 2, 0, 2}\n");
	printf("PE %d: MyB is - ", MyPE);
	for (i = 0; i < 5; i ++)
	{
		printf("%d ", MyB[i]);
	}
	printf("\n");
	clearMyB(MyB);

	MPI_Finalize();
	return 0;
}