Sperm is a random permutations generator based on the ideas of group theory that allows you to generate very large permutations without extra memory consumption.
Add this line to your application's Gemfile:
gem 'sperm'And then execute:
$ bundleOr install it yourself as:
$ gem install spermSperm.rand(5).each { |element| puts element }This is a shorthand for:
Sperm::RandomPermutations.new(5).rand.each { |element| puts element }You can also use your own source of randomness:
Sperm::RandomPermutations.new(5, Random.new(42))
Sperm::RandomPermutations.new(10**8, SecureRandom)| Operation | Time complexity | Space complexity |
|---|---|---|
| Initialization | O(n/ϕ(n) · log(n)) | O(1) |
| Generation of next element | O(1) | O(1) |
Copyright © 2014 Arthur Khashaev. See LICENSE.txt for details.