DouKaku?

import    java.util.Date
import    java.text.SimpleDateFormat

object Prime {
    private def from(n:Int):Stream[Int] =
        Stream.cons(n, from(n + 1))
    
    private def sieve(s:Stream[Int]):Stream[Int] =
        Stream.cons(s.head,sieve(s.tail.filter { _ % s.head != 0 }))
    
    def primes = sieve(from(2))
}

class Meertens(max:BigInt) {
    val    width:Int = max.toString.length
    val    primes:Stream[Int] = Prime.primes.take(width)
    var    _meertenses:List[BigInt] = List()
    
    def this() = this(BigInt.apply("9999999999"))
    
    def meertenses_=(meertenses:List[BigInt]) = _meertenses = meertenses
    def meertenses = _meertenses
    
    def search:Meertens = {
        def _search(depth:Int,number:BigInt,goedel:BigInt):Unit = {
            val    prime = BigInt.apply(primes.apply(depth))
            (new Range(0,9,1)).foreach { d =>
                val    n = number * 10 + d
                val    g = goedel * prime.pow(d)
                if (n == g) meertenses = n::meertenses
                if ((g < max) && (depth < width - 1)) _search(depth + 1,n,g)
            }
        }
        _search(0,0,1)
        this
    }
}

object Main {
    def main(args:Array[String]):Unit = {
        var    max:String = args.length match { case 0 => "9999999999"; case _ => args(0) }
        printf("start:%s\n",new SimpleDateFormat("yyyy/MM/dd HH:mm:ss").format(new Date))
        (new Meertens(BigInt.apply(max))).search.meertenses.foreach { m => println(m.toString) }
        printf("end:%s\n",new SimpleDateFormat("yyyy/MM/dd HH:mm:ss").format(new Date))
    }
}