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

void main(int argc, char *argv[]) 
{ 
    int rank; 
    double param, sum; 
    MPI_Init(&argc, &argv); 
    MPI_Comm_rank(MPI_COMM_WORLD,&rank); 
    if(rank==2) param = 23.0; 
    MPI_Bcast(&param, 1, MPI_DOUBLE, 2, MPI_COMM_WORLD); 
    MPI_Reduce(&param, &sum, 1, MPI_DOUBLE, MPI_SUM, 0, MPI_COMM_WORLD); 
    if(rank == 0)printf("P:%d, sum is %f \n",rank, sum); 
    MPI_Finalize(); 
}