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

int main(int argc, char** argv) {
    // Initialize the MPI environment
    MPI_Init(NULL, NULL);

    // Get the number of processes
    int world_size;
    MPI_Comm_size(MPI_COMM_WORLD, &world_size);

    // Get the rank of the process
    int world_rank;
    MPI_Comm_rank(MPI_COMM_WORLD, &world_rank);

    // Get the name of the processor
    char processor_name[MPI_MAX_PROCESSOR_NAME];
    int name_len;
    MPI_Get_processor_name(processor_name, &name_len);

    // Print off a hello world message
    printf("Hello world from processor %s, rank %d"
           " out of %d processors\n",
           processor_name, world_rank, world_size);

   unsigned long int i;
   double sum;
   int sign;
   
   srand(world_rank+1);
   
   unsigned long int N = 10000000000;
   
   unsigned long int N_CURRENT_PROC = N / world_size;
   
   for (i=world_rank*N_CURRENT_PROC; i < (world_rank+1)*N_CURRENT_PROC; i++)
   {
      sign = rand();
      if (sign > RAND_MAX/2)
          sign = 1;
      else
          sign = -1;
          
      sum += sign*rand();
   }

    printf("THREAD %d: %f\n",world_rank,sum);

    // Finalize the MPI environment.
    MPI_Finalize();
}