/*
  file: bcast2.c
  compile: cc bcast2.c -lmpi
  run: mpirun -np 4 ./a.out
*/

#include "mpi.h" 

main( argc, argv ) 
int argc; 
char **argv; 
{
    int myrank; 
    int p;
    int sum, v;
    int i;
    MPI_Status status;
    MPI_Init( &argc, &argv ); 
    MPI_Comm_rank( MPI_COMM_WORLD, &myrank ); 
    MPI_Comm_size( MPI_COMM_WORLD, &p ); 

    v = 10;
    MPI_Bcast (&v, 1, MPI_INT, 0, MPI_COMM_WORLD);

    if (myrank == 0){
      sum = 0;
      for (i=1; i<p; i++){
	MPI_Recv(&v, 1, MPI_INT, i, 99, MPI_COMM_WORLD, &status);
	sum = sum + v;
      }
    }
    else{
      v = v * myrank;
      MPI_Send(&v, 1, MPI_INT, 0, 99, MPI_COMM_WORLD);
    }

    if (myrank == 0){
      printf("sum of all ranks*v = %d\n", sum);
    }
    MPI_Finalize(); 
  }