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

const int MAXITEMS = 10;

int main(int argc, char **argv)
{
    int size;
    int rank;
    int value=34567;
    int root=0;
    int array[MAXITEMS];
    int i;
    int anytag =0;
    int sum, totalsum;
    MPI_Status status;
    
    MPI_Init(&argc, &argv);
    MPI_Comm_size(MPI_COMM_WORLD, &size);
    MPI_Comm_rank(MPI_COMM_WORLD, &rank);
    if (rank == 0)
    {
       srand(time(0));
   
       for (i=0; i < MAXITEMS; i++)
       {
           array[i] = rand() % 100;
       }
       printf("Here's the entire array from process %d: (starts on address %u)\n",
                   rank, array);
       for (i=0; i < MAXITEMS; i++)
       {
           printf("%d ", array[i]);
       }
       printf("\n");	
     
    //Send the array to each process other then process 0 (root process)
       for (i=1; i < size; i++)
       {
          MPI_Send(array, MAXITEMS, MPI_INT, i, anytag, MPI_COMM_WORLD);
       }
    }

    else {
       MPI_Recv(array, MAXITEMS, MPI_INT, 0, anytag, MPI_COMM_WORLD, &status);
       printf("Hello from process %d out of %d Received:\n", 
               rank, size);
       printf("(starts on address %u)\n", array);
       for (i=0; i < MAXITEMS; i++)
       {
          printf("%d ", array[i]);
       }
       printf("\n");
     }
     sum = 0;
     for (i=0; i < MAXITEMS; i++)
     {
         sum = sum + array[i];
     }
     MPI_Reduce(&sum, &totalsum, 1, MPI_INT, MPI_SUM, 0, MPI_COMM_WORLD);
     printf("Process: %d, Sum = %d\n", rank, sum);
     if (rank == 0)
        printf("*** Reporting from ROOT: Totalsum = %d ***\n", totalsum);
     
    MPI_Finalize();
    return 0;
}

/*

mpirun N sendArray2
Here's the entire array from process 0: (starts on address 3221223488)
44 60 28 40 71 59 2 96 5 60 
Hello from process 2 out of 6 Received:
(starts on address 3221223744)
44 60 28 40 71 59 2 96 5 60 
Hello from process 1 out of 6 Received:
(starts on address 3221223744)
44 60 28 40 71 59 2 96 5 60 
Process: 1, Sum = 465
Hello from process 3 out of 6 Received:
(starts on address 3221223744)
44 60 28 40 71 59 2 96 5 60 
Process: 3, Sum = 465
Process: 2, Sum = 465
Hello from process 5 out of 6 Received:
(starts on address 3221223744)
44 60 28 40 71 59 2 96 5 60 
Process: 5, Sum = 465
Process: 0, Sum = 465
*** Reporting from ROOT: Totalsum = 2790 ***
Hello from process 4 out of 6 Received:
(starts on address 3221223744)
44 60 28 40 71 59 2 96 5 60 
Process: 4, Sum = 465


*/