class Integer

Public Instance Methods

choose(k) click to toggle source
# File lib/core/util.rb, line 2
def choose(k)
  # binominal coefficient
  return self.factorial / ((self -k).factorial * k.factorial)
end
factorial() click to toggle source
# File lib/core/util.rb, line 7
def factorial()
  # n!
  return (1..self).inject(1, &:*)
end