Project Euler Problem 16

Problem 16

03 May 2002

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?

Answer: 1366

C#

 

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Numerics;

namespace Euler {
    class Program {
        static void Main(string[] args) {
            Console.WriteLine(BigInteger.Pow(2, 1000).ToString().ToCharArray().Select(x => x - '0').Sum());
            Console.ReadKey();
        }
    }
}

Racket

 

(define (char->digit x)
  (- (char->integer x)
     (char->integer #\0)))

(define (problem16)
  (display (apply + (map char->digit (string->list (number->string (expt 2 1000)))))))

(problem16)