/* Compare to ptr2.c. */

void swap(int *p,int *q)
{
  int tmp;

  tmp = *p;
  *p = *q;
  *q = tmp;
}

int main(void)
{
  int x = 3;
  int y = 11;

  printf("%d %d\n",x,y);
  swap(&x,&y);
  printf("%d %d\n",x,y);
  return 0;
}