145 is a curious number, as 1! + 4! + 5! = 1 + 24 + 120 = 145.

Find the sum of all numbers which are equal to the sum of the factorial of their digits.

Note: as 1! = 1 and 2! = 2 are not sums they are not included.

+-#factorial
def factorial(n)
  return 1 if n<2
  (2..n).inject{|u,v|u*v}
end

+-#Enumerable
module Enumerable
  def sum
    self.inject{|u,v|u+v}
  end
  def product
    self.inject{|u,v|u*v}
  end
  def count(ob)
    self.select{|i|i==ob}.length
  end
  def take_while
    return [] unless yield(self.first)
    if(self.class==Range)
      evalPoint=self.first
      evalPoint=evalPoint.succ while yield(evalPoint.succ) and not evalPoint==self.last
      return self.first..evalPoint
    else
      s=self.to_a
      upTo=1
      upTo+=1 while yield(s[upTo]) and upTo<self.length
      return self[0...upTo]
    end
  end
end

+-#dig_split
def dig_split(n)
  s=n.to_s
  s.split("").map{|i|i.to_i}
end

+-#repeat_combos
def repeat_combos(selectFrom,totalDigits)
  return [] if selectFrom==[]
  return [[selectFrom.first]*totalDigits] if(selectFrom.length==1)
  return selectFrom.map{|i|[i]} if totalDigits==1
  ret=[]
  selectFrom.each do |a|
    1.upto(totalDigits-1) do |b|
      c=repeat_combos(selectFrom[(selectFrom.index(a)+1)..-1],totalDigits-b)
      c.each{|d|ret.push(([a]*b)+d)}
    end
    ret.push([a]*totalDigits)
  end
  ret
end

def p34
  fax=(0..9).map{|i|factorial(i)}
  puts (2..7).map{|i|repeat_combos((0..9).to_a,i)}.inject{|u,v|u+v}.
  	select{|a|a==dig_split(a.map{|i|fax[i]}.sum).sort}.map{|a|a.map{|i|fax[i]}.sum}.sum
end