2¹⁵ = 32768 and the sum of its digits is 3 + 2 + 7 + 6 + 8 = 26.

What is the sum of the digits of the number 2¹⁰⁰⁰?

+-;digit-split
(defn digit-split [n] 
  (map #(- (int %) 48) (str n))
)

+-;pow
(defn pow [a b]
  (loop [res 1 mult a shift b]
    (if (= 0 shift)
      res
      (if (= 1 (rem shift 2))
        (recur (* res mult) (* mult mult) (bit-shift-right shift 1))
        (recur res (* mult mult) (bit-shift-right shift 1))
      )
    )
  )
)

(defn p16 []
  (println
    (apply + (digit-split (pow 2 1000)))
  )
)

+-%digit_split
digit_split(N)->
	lists:map(fun(X)->X-48 end,integer_to_list(N)).

+-%pow
pow(_,0)->1;
pow(1,_)->1;
pow(A,B)->pow(A,B,1).
pow(_,0,Res)->Res;
pow(Mult,B,Res) when B band 1 == 1 ->
	pow(Mult*Mult,B bsr 1, Res*Mult);
pow(Mult,B,Res)->pow(Mult*Mult,B bsr 1, Res).

p16()->io:format("~w~n",[lists:sum(digit_split(pow(2,1000)))]).

+-#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

def p16
  puts dig_split(2**1000).sum
end

+-//pow
def pow(a: BigInt, b: Int)={
  def loop(res: BigInt, mult: BigInt, shift:Int): BigInt={
    if(shift==0) res
    else{
      if(shift%2==0) loop(res, mult*mult, shift >> 1)
      else loop(res*mult, mult*mult, shift >>1)
    }
  }
  loop(1,a,b)
}

+-//digitSplit
def digitSplit(n: BigInt)={
  n.toString.map(_.toInt - 48)
}

def p16{
  println(digitSplit(pow(2,1000)).foldLeft(0)(_+_))
}