Beefy Boxes and Bandwidth Generously Provided by pair Networks
Syntactic Confectionery Delight

comment on

( #3333=superdoc: print w/replies, xml ) Need Help??
The proof of concept you offered on your scratch of a TS is producing the same result as Algorithm::Dependency::Ordered (the wrong thing). I am not saying a TS isn't what I need, just that I am not seeing how to convince it to give me the list I want.

In my example above, your code gave me LA -> XYZ -> BLAH which only satisfies rule 1 above. To satisfy rule 2, FOO and 3 other items must also be removed. In other words, it only appears to go down (DFS) not back up. I am honestly not trying to be dense here. The code I am using is below:

#!/usr/bin/perl use strict; use warnings; my %tree = ( FOO => [qw/BAR BLAH ASDF/], BAR => [qw/LA/], BLAH => [qw/XYZ/], ASDF => [qw/OOOOO/], LA => [], XYZ => [qw/LA/], OOOOO => [] ); { my %seen; my %onstack; my @list; sub how_to_uninstall { my $target = shift; (@list, %seen, %onstack) = (); _traverse($target); return @list; } sub _traverse { my $x = shift; $seen{$x} = $onstack{$x} = 1; for my $y (@{$tree{$x}}) { die "cyclic!" if $onstack{$y}; # back edge _traverse($y) unless $seen{$y}; } push @list, $x; $onstack{$x} = 0; } } my @order = how_to_uninstall('BLAH'); print "@order\n";

Cheers - L~R

In reply to Re^2: Algorithm For Uninstalling Dependencies by Limbic~Region
in thread Algorithm For Uninstalling Dependencies by Limbic~Region

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

  • Are you posting in the right place? Check out Where do I post X? to know for sure.
  • Posts may use any of the Perl Monks Approved HTML tags. Currently these include the following:
    <code> <a> <b> <big> <blockquote> <br /> <dd> <dl> <dt> <em> <font> <h1> <h2> <h3> <h4> <h5> <h6> <hr /> <i> <li> <nbsp> <ol> <p> <small> <strike> <strong> <sub> <sup> <table> <td> <th> <tr> <tt> <u> <ul>
  • Snippets of code should be wrapped in <code> tags not <pre> tags. In fact, <pre> tags should generally be avoided. If they must be used, extreme care should be taken to ensure that their contents do not have long lines (<70 chars), in order to prevent horizontal scrolling (and possible janitor intervention).
  • Want more info? How to link or or How to display code and escape characters are good places to start.
Log In?

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

How do I use this? | Other CB clients
Other Users?
Others contemplating the Monastery: (5)
As of 2021-10-28 07:32 GMT
Find Nodes?
    Voting Booth?
    My first memorable Perl project was:

    Results (96 votes). Check out past polls.