pig2

gistfile1.scala

object Succ {
  def main(args: Array[String]) {
    assert(succ("") == "")
    assert(succ("3") == "4")
    assert(succ("R2D3") == "R2D4")
    assert(succ("R293") == "R294")
    assert(succ("R2D9") == "R2E0")
    assert(succ("A99") == "B00")
    assert(succ("Z99") == "AA00")
    assert(succ("Zz99") == "AAa00")
    assert(succ("9Z") == "10A")
    println("finished")
  }

  def succ(expr: List[Char], carry:Char): List[Char] = expr match {
    case Nil => List(carry)
    case ch :: xs => {
      ch match {
        case '9' => '0' :: succ(xs, '1')
        case 'z' => 'a' :: succ(xs, 'a')
        case 'Z' => 'A' :: succ(xs, 'A')
        case x => (x+1).toChar :: xs
      }
    }
  }

  def succ(s:String): String = if(s.isEmpty) "" else succ(s.toList.reverse, '1').reverse.mkString
}