From: Mario Camou <mcamou@...>
Date: 2009-09-21T11:31:01+09:00
Subject: Re: Multi-Dimensional Arrays in Priority Queues

--001636ed70ae8cf01e04740d4587
Content-Type: text/plain; charset=ISO-8859-1

Hi,
In the line:

pq.push([2], [123456780], [123456708])

you're not passing in a multi-dimensional array, you're passing 3 parameters
each of which is an array. Try with:

pq.push([[2], [123456780], [123456708]])

(notice the double [ at the beginning and the  double ] at the end).

you will also have to change your PQueue creation to something like this:

pq=PQueue.new(proc{|x,y| x[0]<y[0]})

Haven't tested this in irb but it (or something very much like it) should
work.

-Mario.

--
I want to change the world but they won't give me the source code.


On Mon, Sep 21, 2009 at 04:25, Mason Kelsey <masonkelsey@gmail.com> wrote:

> In my program I need to construct a priority queue that sorts ascending.
> The basic idea can be expressed in the following simple code that uses a
> Priority Queue concept.  See:
> http://www.math.kobe-u.ac.jp/~kodama/tips-ruby-pqueue.html
>
> 1   require "pqueue"
> 2
> 3   pq=PQueue.new(proc{|x,y| x<y})
> 4   pq.push(2)
> 5   pq.push(3)
> 6   pq.push(4)
> 7   pq.push(3)
> 8   pq.push(2)
> 9   pq.push(4)
> 10 print "size:"+pq.size.to_s+"\n"
> 11 print "each_pop: "
> 12 pq.each_pop{|x| print x.to_s+" "}
> 13 print "\n"
>
> This is clean and simple to understand.  But I need to be able to put into
> the queue several components per push to make an entire record object.  I
> need to have three components: an integer heuristic value, followed by two
> 9
> digit configuration patterns, such as
> pq.push([2], [123456780], [123456708])  But this gives me an argument error
> message:
> pqueue.rb:4:in `push': wrong number of arguments (3 for 1)
> (ArgumentError) from pqueue.rb:4
>
> or pq.push(2_123456780_123456708) ignores the underscore separators and
> runs
> the 3 parts together as one long number.
>
> Still learning Ruby and none of the books address multiple dimensional
> arrays very well.  Is the Priority Queue not able to handle
> multi-dimensional arrays?  Can this code be modified to allow
> multi-elements
> in each push and still sort on the first element?
>
> If I cannot use pqueue, is there another required library of methods that
> will work with three elements in each array entry?
>
> Thanks in advance to those of you who can help.  And thanks to all who help
> out on this forum.  Very good forum.
>
> No Sam
>

--001636ed70ae8cf01e04740d4587--