Class: Integer

Inherits:
Object
  • Object
show all
Defined in:
lib/core/util.rb

Instance Method Summary collapse

Instance Method Details

#choose(k) ⇒ Object 



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# File 'lib/core/util.rb', line 2

def choose(k)
  # binominal coefficient
  return self.factorial / ((self -k).factorial * k.factorial)
end

#factorial ⇒ Object 



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# File 'lib/core/util.rb', line 7

def factorial()
  # n!
  return (1..self).inject(1, &:*)
end