// Generate a random number. If the value of the random number is multiple of 3, 
// then display the old random number that is already displayed and display the 
// current random number in one line.
 
#include <iostream.h>
#include <time.h>
#include <stdlib.h>

void check_random(unsigned &, unsigned);

int main()
{
  unsigned before, now;
  int counter = 0;

  srand (time(0));
  before = 0;

  while (counter < 20) {
    now = rand();
    check_random(before, now);
    counter++;
  }

  return 0;
}


void check_random(unsigned &old_random, unsigned cur_random)
{
  if ((cur_random % 3) == 0) {
    cout << "old random : " << old_random << " and current random : " << cur_random << "\n";
    old_random = cur_random;
  }
}