I observe that your L's and H's don't move, and that the last two terms are dictated by the first two. This means your pattern can be generated fairly simply with 
#!/usr/bin/perl -w
use strict;

for my $h (1 .. 2) {
    for my $l (1 .. 2) {
        printf "L%dH%dL%dH%d\n", $l, $h, 3-$l, 3-$h;
    }
}

[download]

Obviously, scaling this up to 500 positions and 10 groups is non-trivial, but should be doable similarly. If you need arbitrary complexity, you'll probably want to generate a work queue rather than having fixed nested for loops.

#11929 First ask yourself `How would I do this without a computer?' Then have the computer do it the same way.

In reply to Re: How can one generate all possible combinations with reference to string positions? by kennethk
in thread How can one generate all possible combinations with reference to string positions? by supriyoch_2008

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.