Beefy Boxes and Bandwidth Generously Provided by pair Networks
We don't bite newbies here... much
 
PerlMonks  

Comment on

( #3333=superdoc: print w/ replies, xml ) Need Help??
Yow. I'm not sure who's crazier - you for suggesting this might be something one would want to do, or me for trying to do it ;)

Because It's There, as the man said.

Having struggled with it a bit I realised one thing about the question itself, which is that we can't say there are only three patterns. In fact there are a lot more - "hell", "hel", and "he" to name but the most obvious additions. That's unless we want to match against a dictionary, in which case it's just a matter of processing power.

Assuming we are interested in patterns rather than specific words I think the following does it. I should say at the outset that the clever bit in this comes from japhy's regex book which is referred to in this node.
my $string = "helloworldhellohellohihellohiworld"; my $length = length $string; my $window = int (($length - 2) / 2); # use japhy's regex to hoover up all char # sequences that MIGHT be patterns: my @pats; my $regex; while ($window > 1) { $regex = '(?=(' . '.' x $window . '))'; push @pats, ($string =~ /$regex/g); $window --; } # now go through @pats to find the duplicates # and print the final result @pats = sort @pats; my %dups; for (2 .. $#pats) { $dups{$pats[$_]} ++ if ($pats[$_] eq $pats[$_ - 1]) } $dups{$_} ++ for keys %dups; for (keys %dups) {print $dups{$_},' occurrences of "',$_,'"',"\n"}
This throws up 31 patterns, with up to four occurrences each. (BTW, in case $window doesn't make sense, I assumed (A) there must be at least two occurrences of each pattern, otherwise it wouldn't really be a pattern; (B) each pattern must be at least 2 chars and (C) there must be at least 2 patterns.)

Thanks for making me think. Can I stop now?

George Sherston

In reply to Re: Patter Finding by George_Sherston
in thread Pattern Finding by artist

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!
  • 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, 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, 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.
  • Log In?
    Username:
    Password:

    What's my password?
    Create A New User
    Chatterbox?
    and the web crawler heard nothing...

    How do I use this? | Other CB clients
    Other Users?
    Others avoiding work at the Monastery: (10)
    As of 2015-07-07 23:33 GMT
    Sections?
    Information?
    Find Nodes?
    Leftovers?
      Voting Booth?

      The top three priorities of my open tasks are (in descending order of likelihood to be worked on) ...









      Results (93 votes), past polls