module Combinatorics::PowerSet

Public Class Methods

P(n) click to toggle source

Wrapper function for power set cardinality method defined above

@note The letter `P' stands for the power set function in the context of

statements regarding discrete mathematics.
# File lib/combinatorics/power_set/cardinality.rb, line 32
def self.P(n)
  cardinality(n)
end
cardinality(n) click to toggle source

Get number of elements in power set from number of elements in input set.

@param [Fixnum] n

Number of elements input set.

@return [Fixnum]

Number of elements in power set.

@see Math::factorial @see en.wikipedia.org/wiki/Cardinality

@note

Cardinality of power set on an empty set equals `factorial(0)`
equals 1
# File lib/combinatorics/power_set/cardinality.rb, line 22
def self.cardinality(n)
  Math.factorial(n)
end