class MoreMath::Permutation

def cycles

# => [[3, 6], [4, 5]]
perm.cycles
# => #
perm = Permutation.new(7, 23)
Example:

new Permutation instance with the Permutation.from_cycles method.
The return value of this method can be used to create a
Returns the cycles representation of this Permutation instance. 
def cycles
  perm = value
  result = [[]]
  seen = {}
  current = nil
  loop do
    current or current = perm.find { |x| !seen[x] }
    break unless current
    if seen[current]
      current = nil
      result << []
    else
      seen[current] = true
      result[-1] << current
      current = perm[current]
    end
  end
  result.pop
  result.select { |c| c.size > 1 }.map do |c|
    min_index = c.index(c.min)
    c[min_index..-1] + c[0...min_index]
  end
end