1  #include <stdio.h>
       2  
       3  extern int select ();
       4  extern int f1 (int);
       5  extern int f2 (int);
       6  
       7  int main (void)
       8  {
       9    switch (select ())
      10      {
      11      case 1:
      12        printf ("%d\n", f1 (3));
      13        break;
      14      case 2:
      15        printf ("%d\n", f2 (4));
      16        break;
      17      default:
      18        printf ("%d\n", f2 (0));
      19        break;
      20      }
      21    return 0;
      22  }