module Combinatorics::Derange

Public Class Methods

D(n) click to toggle source

Wrapper for derangement cardinality method defined above

@note The letter `D' is academic representation for derangements

# File lib/combinatorics/derange/cardinality.rb, line 19
def self.D(n)
  cardinality(n)
end
cardinality(n) click to toggle source

Compute the number of derangements for a data structure of given size

@see Math.subfactorial

# File lib/combinatorics/derange/cardinality.rb, line 10
def self.cardinality(n)
  Math.subfactorial(n)
end