Re: Is it possible to make reference to substrings and sort them?

[choroba]

This is how I implemented BW for Rosalind.info:

my @suff = 0 .. length $string;
pop @suff;
@suff = sort { substr($string, $a) cmp substr $string, $b } @suff;

for my $idx (@suff) {
    print substr $string, $idx - 1, 1;
}
print "\n";

Update: Now I noticed they mentioned O(|Text|) solution wasn't needed in the Note.

[hdb]

Your algorithm is somewhat different from the OP's in that you do not sort cyclic rotations at all, only the variable length endings of the text.