Knapsacker

Knapsacker is a Knapsack problem solver in Ruby, using branch and bound algorithm.

It has a simple API and may solve problems in your holiday programming. (That is, it's not optimized. Yet.)

Add this line to your application's Gemfile:

gem 'knapsacker'

And then execute:

$ bundle

Or install it yourself as:

$ gem install knapsacker

First, instanciate Knapsacker with an array of your items. The items must respond to value and cost. And a keyword argument capacity is mandatory. e.g.:

Item = Struct.new(:value, :cost)
knapsacker = Knapsacker.new([Item.new(3, 4), Item.new(4, 5)], capacity: 5)

Then call pack:

items_to_take = knapsacker.pack

It will return items you should take.

There are some knapsack problem solver in Ruby but none has API. (Some of them accepts items as command line arguments or data in file.)

• danielsellergren/ruby-knapsack ... Accepts command line arguments
• sucanjan/knapsack-solver ... Accepts data files, Gnuplot-able
• soulcutter/no_change_please ... Accepts a data file
• mertbulan/knapsack-problem ... No API
• pedroperrone/knapsack-problem ... No API
• shouheiyamauchi/KnapsackProblemSolver ... No API
• Adacchi3/KnapsackProblem ... No API
• sas145alex/knapsack_greedy ... No API
• bsmlima/connected-knapsack ... No README
• mhartman4/fanduel-scrape ... No README

• 1.0
  • Interface to support the general form of Knapsack problem, including:
    • Multiple inequality constraints
    • Multiple equality constraints
  • Spport for items that have interface other than value and cost
• 1.1
  • Some optimization, maybe. Either in C, either with some smarter algorithm.

After checking out the repo, run bin/setup to install dependencies. Then, run rake spec 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.

Bug reports and pull requests are welcome on GitHub at https://github.com/irohiroki/knapsacker. 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.

Everyone interacting in the Knapsacker project’s codebases, issue trackers, chat rooms and mailing lists is expected to follow the code of conduct.