my (@chunks, @fbits, @lbits);
.....
.....
do_chunk(\@chunks, \@fbits, \@lbits);
....
....

sub do_chunk
{
my ($chunks, $fbits, $lbits) = @_;
my (@prefix, $idx1, $idx2, $size);
	
# Find common prefix.  After that, next bit is 0 for $fbits and 1 for
# $lbits is 1.  A split a this point guarantees the longest suffix.
		
$idx1 = 0;
$idx1++
while ($idx1 <= $#$fbits and $$fbits[$idx1] eq $$lbits[$idx1]);
@prefix = @$fbits[0 .. $idx1 - 1];
	
$idx2 = $#$fbits;
$idx2--
while ($idx2 >= $idx1 and $$fbits[$idx2] eq '0' and $$lbits[$idx2] eq '1');
	
# Split if $fbits and $lbits disagree on the length of the chunk.
		
if ($idx2 >= $idx1)
{
$size = $#$fbits - $idx1;
do_chunk ($chunks, $fbits, [ @prefix, (split //, '0' . '1' x $size) ]);
do_chunk ($chunks, [ @prefix, (split //, '1' . '0' x $size) ], $lbits);
}
else
{
$size = $#$fbits - $idx2;
push @$chunks, [ (bits2num( [ @prefix, (split //, '0' x $size) ])), @$fbits - $size ];
}
}

##</code><code>##

if ($idx2 >= $idx1)
{
$size = $#$fbits - $idx1;
do_chunk ($chunks, $fbits, [ @prefix, (split //, '0' . '1' x $size) ]);
do_chunk ($chunks, [ @prefix, (split //, '1' . '0' x $size) ], $lbits);
}