by July 17, 2012

onThis will be the solution of the sixteenth problem of Project Euler:

2^15 = 32768 and the sum of its digits is 3 + 2 + 7 + 6 + 8 = 26.

What is the sum of the digits of the number 2^1000?

I am using my own version of `pow`

here because it seems that the scala standard method from `scala.math`

does not support `BigInt`

which is obviously needed for this problem (or at least for my way of solving it *g*).

```
class Euler016 extends Euler {
def number = 16
def solution = {
def pow(base : Int, n : Int) = {
def inner(base : BigInt, exp : Int, sum : BigInt) : BigInt = {
exp match {
case 1 => sum
case _ => inner(base, exp-1, sum * base)
}
}
inner(BigInt(base), n, BigInt(1))
}
val sum = pow(2, 1000).toString()
sum.foldLeft(0)((s, c) => s + Character.getNumericValue(c))
}
}
```