factorial_flight

Patches 4 different solutions for factorials onto Fixnum.

I get asked to calculate factorials in interviews as an example of recursion all the time, so here you go.

Can we talk about how I solve the real problems facing your product or business now?

Installation

Add this line to your application's Gemfile:

gem 'factorial_flight'

And then execute:

$ bundle

Or install it yourself as:

$ gem install factorial_flight

Usage

2.0.0p247 :001 > require 'factorial_flight'
 => true
2.0.0p247 :002 > 5.factorial
 => 120
2.0.0p247 :003 > 6.factorial(:recursive)
 => 720
2.0.0p247 :004 > -1.factorial
 => "Can not calculate factorial of a negative number"
2.0.0p247 :005 >

Included in the available options for #factorial:

:gamma : Uses Math::gamma(n+1) :inject : Default - Uses Enumerable's #inject method :loop : Uses a loop to iterate over the range of integers included in the factorial :recursive : Perhaps what most interviewers are specifically asking for when requiring a candidate to write an algorithm to find factorials

Contributing

1. Fork it ( http://github.com//factorial_flight/fork )
2. Create your feature branch (git checkout -b my-new-feature)
3. Commit your changes (git commit -am 'Add some feature')
4. Push to the branch (git push origin my-new-feature)
5. Create new Pull Request