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

const int MAXROWS = 5;
const int MAXCOLS = 5;

int main(int argc, char **argv)
{
    int size;
    int rank;
    int value=34567;
    int root=0;
    int matrix[MAXROWS][MAXCOLS];
    int i, j;
    int anytag =0;
    int sum, totalsum, rowToSend;
    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 < MAXROWS; i++)
       {
         for (j = 0; j < MAXCOLS; j++)
         {
             matrix[i][j] = rand() % 100;
         }
       }
       printf("Here's the entire array from process %d: (starts on address %u)\n",
                   rank, matrix);
       for (i=0; i < MAXROWS; i++)
       {
          for (j = 0; j < MAXCOLS; j++)
	  {
              printf("%5d ", matrix[i][j]);
          }
	  printf("\n");
       }
       printf("\n");	
     
    //Send the array to each process other then process 0 (root process)
       for (i=1; i < size; i++)
       {
          rowToSend = i % MAXROWS;
	  MPI_Send(&rowToSend, 1, MPI_INT, i, anytag, MPI_COMM_WORLD);
          MPI_Send(matrix[rowToSend], MAXCOLS, MPI_INT, i, anytag, 
	           MPI_COMM_WORLD);
       }
    }

    else {
       MPI_Recv(&rowToSend, MAXCOLS, MPI_INT, 0, anytag, MPI_COMM_WORLD, &status);
       MPI_Recv(matrix[rowToSend], MAXCOLS, 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", matrix);

       printf("Here's row %d from process %d:\n", rowToSend, rank);
       for (j = 0; j < MAXCOLS; j++)
       {
           printf("%5d ", matrix[rowToSend][j]);
       }
       printf("\n");
       
     }

    MPI_Finalize();
    return 0;
}

/*

mpirun N sendMatrix2
Here's the entire array from process 0: (starts on address 3221223408)
   34     7    80    32    14 
   35    66    61    60    37 
   69    89    53    83     2 
   14    81    46    86    35 
    3     7    24    86    72 

Hello from process 1 out of 6 Received:
(starts on address 3221223664)
Here's row 1 from process 1:
   35    66    61    60    37 
Hello from process 2 out of 6 Received:
(starts on address 3221223664)
Here's row 2 from process 2:
   69    89    53    83     2 
Hello from process 3 out of 6 Received:
(starts on address 3221223664)
Here's row 3 from process 3:
   14    81    46    86    35 
Hello from process 4 out of 6 Received:
(starts on address 3221223664)
Here's row 4 from process 4:
    3     7    24    86    72 
Hello from process 5 out of 6 Received:
(starts on address 3221223664)
Here's row 0 from process 5:
   34     7    80    32    14 

*/