Pque

100%　rubyで作ったプライオリティーキューです。 Priority Que for ruby. ヒープツリーを利用しています。 Implementing Heap tree on Array, child1 as i*2 + 1, child2 as i*2 + 2.

Add this line to your application's Gemfile:

gem 'pque'

And then execute:

$ bundle

Or install it yourself as:

$ gem install pque

require 'pque'

pq = Pque.new # for descending order
pq.push(1)
pq.push(5)
pq.push(4)
pq.push(3)
pq.pop    #=> 5
pq.pop    #=> 4
pq.push(2)
pq.pop    #=> 3
pq.pop    #=> 2
pq.pop    #=> 1

pq = Pque.new(false) # for ascending order
falseのときダイクストラ法でよく使われる小さい順となります。

ウエイト付きのデータをキューに入れるには構造体をclassにして、include Comparableのうえ
<=>演算子をウエイトを比較するように再定義して使ってください。

class Data
  attr_accessor :data,:weight
  include Comparable
  def initialize(data,weight)
    @data = data
    @weight = weight
  end
  def <=>(other)
    @weight <=> other.weight
  end
end

que = Pque.new(false)
que.push(Data.new("Hoge",3))
que.push(Data.new("Fuga",2))
que.push(Data.new("HogeFuga",5))
que.pop #=> #<@data="Fuga",@weight=2>
que.pop #=> #<@data="Hoge",@weight=3>
que.pop #=> #<@data="HogeFuga",@weight=5>

After checking out the repo, run bin/setup to install dependencies. Then, run rake test to run the tests. You can also run bin/console for an interactive prompt that will allow you to experiment.

To install this gem onto your local machine, run bundle exec rake install. To release a new version, update the version number in version.rb, and then run bundle exec rake release, which will create a git tag for the version, push git commits and tags, and push the .gem file to rubygems.org.

Bug reports and pull requests are welcome on GitHub at https://github.com/[USERNAME]/pque. This project is intended to be a safe, welcoming space for collaboration, and contributors are expected to adhere to the Contributor Covenant code of conduct.

The gem is available as open source under the terms of the MIT License.