Pathologically Eclectic Rubbish Lister PerlMonks

### comment on

 Need Help??
Despite what I just said about NP-completeness, the following algorithm might give a reasonable solution (certainly not optimal).
1. Let C be the set of all complaints.
2. For each complaint c in C find the set S(c) of all complaints d in C such that the distance between c and d is less than X (X is user defined).
3. Find complaint e in C such that |S(e)| <= |S(f)| for all f in C; that is, find the complaint who has the most other complaints nearby. Pick a random one in case of a tie.
4. Make a clump out of e and S(e).
5. Remove all complaints g in S(e) from C. For all h remaining in C, remove from S(h) all g in S(e).
6. If C is empty, we're done. Else, goto 3.
Some pseudo code:
```# Get set of all complaints.
my @C = get_all_complaints;
# Find all the associated sets.
my %D = map {my \$c = \$_;
\$c => {map  {\$_ => 1}
grep {\$c ne \$_ && distance (\$c, \$_) < \$X} @C}} @C;
while (%D) {
# Find complaint with the most nearby.
my (\$complaint, \$size) = (undef, 0);
while (my (\$c, \$set) = each %D) {
(\$complaint = \$c, \$size = keys %\$set) if keys %\$set > \$size;
}
# Found largest, make a clump.
make_clump (\$complaint, @{\$D {\$complaint}});
# Delete largest from set.
my \$set = delete \$D {\$complaint};
# Delete associated set from set.
delete @D {keys %\$set};
# Delete associated set from associated sets.
delete @{\$_} {keys %\$set} for values %D;
}
The performance will be quadratic, I'm afraid.

Abigail

Title:
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 How to display code and escape characters are good places to start.

Create A New User
Domain Nodelet?
Chatterbox?
and the web crawler heard nothing...

How do I use this? | Other CB clients
Other Users?
Others lurking in the Monastery: (4)
As of 2022-12-05 10:36 GMT
Sections?
Information?
Find Nodes?
Leftovers?
Voting Booth?

No recent polls found

Notices?