/*  p. 506, A Book on C, by Al Kelley and Ira Pohl  */

#include <stdio.h> 
#include <time.h> 

  int  fib(int);
  int  fork(void);
  void  sleep(unsigned);

main()
{
  int  begin = time(NULL),i;

  if (fork() == 0)                       /*child*/
    for (i = 0; i < 30; ++i)
      printf("fib(%2d) = %d\n", i, fib(i));
  else                                   /*parent*/
    for (i=0;  i < 30; ++i){
      printf("elapsed time = %d\n", time(NULL) - begin);
    }
}
 
int fib(int n)
{
  if (n <= 1)
    return n;
  else
    return (fib(n-1) + fib(n-2));
}