correcciones de problemas de MPI

alguien me paso el tip de que el broadcast de MPI es una operacion colectiva y que no tiene que ir en el rank 0 si no que todos lo tienen que ejecutar ya que tiene el receive implicito, asi que aca los 2 programas corregidos (los que no imprimian los valores de los procesos que no fueran el master).

plus un arreglo en la declaracion de la estructura en el segundo programa.

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

int main (int argc, char** argv) {
 int rank, size, value, i;
 MPI_Status status;

 MPI_Init (&argc, &argv);   /* starts MPI */
 MPI_Comm_rank (MPI_COMM_WORLD, &rank);        /* get current process id */
 MPI_Comm_size (MPI_COMM_WORLD, &size);        /* get number of processes */

 do {
  if(rank == 0) {
   printf("give me a value: ");
   scanf("%d", &value);
  }

  MPI_Bcast(&value, 1, MPI_INT, 0, MPI_COMM_WORLD);
  printf("process %d received %d\n", rank, value);
  fflush(stdout);
 } while(value >= 0);
 printf("negative value, closing\n");

 MPI_Finalize();
 return 0;
}

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

MPI_Datatype IntDoubleType = 0;

typedef struct {
 int value_int;
 double value_double;
}IntDouble;

MPI_Datatype create_int_double_type() {
 if(IntDoubleType == 0) {
  MPI_Aint array_of_displacements[2];
        MPI_Datatype array_of_types[2];
        int array_of_blocklengths[2];

        array_of_displacements[0] = 0;
        array_of_types[0] = MPI_INT;
        array_of_blocklengths[0] = sizeof(int);

        array_of_displacements[1] = sizeof(int);
        array_of_types[1] = MPI_DOUBLE;
        array_of_blocklengths[1] = sizeof(double);

        MPI_Type_struct(1, array_of_blocklengths, array_of_displacements,
                        array_of_types, &IntDoubleType);
        MPI_Type_commit(&IntDoubleType);

 }

 return IntDoubleType;
}

int main (int argc, char** argv) {
 int rank, size, value_int, i;
 double value_double;
 IntDouble value;
 MPI_Status status;

 MPI_Init (&argc, &argv);   /* starts MPI */
 MPI_Comm_rank (MPI_COMM_WORLD, &rank);        /* get current process id */
 MPI_Comm_size (MPI_COMM_WORLD, &size);        /* get number of processes */
 create_int_double_type();

 do {
  if(rank == 0) {
   printf("give me an int value: ");
   scanf("%d", &value_int);
   printf("give me a double value: ");
   scanf("%lf", &value_double);
   value.value_int = value_int;
   value.value_double = value_double;
  }

  MPI_Bcast(&value, 1, IntDoubleType, 0, MPI_COMM_WORLD);
  printf("process %d received %d %lf\n", rank, value.value_int,
    value.value_double);
  fflush(stdout);
 } while(value.value_int >= 0);
 printf("negative value, closing\n");

 MPI_Finalize();
 return 0;
}