Beefy Boxes and Bandwidth Generously Provided by pair Networks
more useful options

Comment on

( #3333=superdoc: print w/replies, xml ) Need Help??
Like I said before, figuring out when to use parens is the tricky part. :) MeowChow pointed out that my solution didn't account for operators which aren't associative ("2 3 4 + -" should be "2 - (3 + 4)" instead of "2 - 3 + 4"). Then I noted that this information was missing from the data provided in the original problem.

I decided to tackle the problem of associativity, and came up with this solution, at 171 characters in the body of the sub:

%o = ('+' => 1, '-' => 1, '*' => 2, '/' => 2, ); %a = ('-' => 1, '/' => 1, ); sub rpn2ltr { for$i(@r=@_){if($p=$o{$i}){$r=$p>($r=pop)->[0]||($p==$r-> [0]&&$a{$i})?"($r->[1])":$r->[1];$l=$p>($l=pop)->[0]?"($l->[ 1])":$l->[1]}push@_,[$p||9,$p?"$l $i $r":$i]}$_[-1][1] }
It's pretty ugly. :/ I hope someone will provide a more elegant solution!

In reply to Re: (Golf) Reversing RPN Notation by chipmunk
in thread (Golf) Reversing RPN Notation by Masem

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, 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?

    What's my password?
    Create A New User
    and all is quiet...

    How do I use this? | Other CB clients
    Other Users?
    Others making s'mores by the fire in the courtyard of the Monastery: (2)
    As of 2018-02-26 01:56 GMT
    Find Nodes?
      Voting Booth?
      When it is dark outside I am happiest to see ...

      Results (316 votes). Check out past polls.