MPI question

Hello to everybody I would welcome some info to my question since I am very new to MPI.
Below is a piece of code where I would like every process that I use to print the Hello message and a random number in the range 0 to x (pick(x). If I run this code I take for every process the same random number. Why? How can I take different? Is the time seed the problem? What can I use? Many thanks on behalf

Code:

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

unsigned time_seed();
int pick(int x);

int main(int argc, char *argv[])
{int i,id,p, rand;
  srand48(time(NULL));
  srand(time_seed());


  MPI_Init(&argc,&argv);
  MPI_Comm_rank(MPI_COMM_WORLD,&id);
  MPI_Comm_size(MPI_COMM_WORLD,&p);

  /* for(i=0; i<p;i++)
    {*/
      rand=pick(5);
      printf("Hello, world from process number %d with rand no %d\n", id, rand);

      /* }*/
 
MPI_Finalize();
return 0;
}

unsigned time_seed()

{
  time_t now =time(0);
  unsigned char *p = (unsigned char *)&now;
 
  unsigned seed=0;
  size_t i;

  for (i=0;i<sizeof now;i++)
    seed = seed * (UCHAR_MAX+2U) + p[i];
  return seed;
}


int pick(int x)

{

static  int p1=0;
        int p2;

        if(p1 == 0)
          {
            srand(time_seed());
            p1=1;
          }

        p2 = (rand()% (x+1));
        return p2;

}

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Is there any way when I call a random number generator to have different random numbers generated in each process

You could incorporate the "rank" in your time_seed() function. This will ensure each process uses a different seed at startup.

/edit Doh, dupe thread

gg

yes that's it thank you very much