Hi guys, I met a problem.
When I tried this script below:
//--------------------------------------------------------------------
sub print_instruction {
my ($disk, $start, $end) = @_;
print "Move disk #$disk from $start to $end.\n";
}
sub hanoi {
my ($n, $start, $end, $extra, $m) = @_;
if ($n == 1) {
$m->(1, $start, $end);
} else {
hanoi($n-1, $start, $extra, $end);
$m->($n, $start, $end);
hanoi($n-1, $extra, $end, $start);
}
}
&hanoi(3, 'A', 'C', 'B', \&print_instruction);
//-------------------------------------------------------------------------
I got a error : Undefined subroutine &main:: called at ....
this is an example in <High Order Perl>, so it should not be wrong, I
just don't known what is the problem.
Plz help me.
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