Gets all permutations of a given number.

permutations.rb

def number_shuffle(number)
  dig = number.to_s.split ''
  if dig.length == 1
    return dig
  end
  out = []
  (0...dig.length).each do |d|
    nums = []
    if d > 0
      nums = nums << dig[0..d-1]
    end
    if d < dig.length-1
      nums = nums << dig[d+1..dig.length-1]
    end
    number_shuffle( nums.join('').to_i ).each do |i|
      out.push (i.to_s + dig[d].to_s).to_i
    end
  end
  out.sort
end