class Integer

Public Instance Methods

combination(k) click to toggle source
# File lib/oh_my_method/integer.rb, line 10
def combination(k)
  self.factorial/(k.factorial*(self-k).factorial)
end
factorial() click to toggle source
# File lib/oh_my_method/integer.rb, line 18
def factorial
  return 1 if self.zero?
  (1..self).inject(:*)
end
minus?() click to toggle source
# File lib/oh_my_method/integer.rb, line 6
def minus?
  self < 0
end
permutation(k) click to toggle source
# File lib/oh_my_method/integer.rb, line 14
def permutation(k)
  self.factorial/(self-k).factorial
end
plus?() click to toggle source
# File lib/oh_my_method/integer.rb, line 2
def plus?
  self > 0
end