Select Code to Download

#!/usr/bin/perl

...

hanoi( $disk, 'A', 'B', 'C', \&check_move );
hanoi( $disk, 'A', 'B', 'C', \&hprint );

Use of uninitialized value in subroutine entry at hanoi.pl line 33.
Can't use string ("") as a subroutine ref while "strict refs" in use a
+t hanoi.pl line 33.