주어진 숫자에서 모든 숫자의 곱 찾기

다음은 OP의 재귀 솔루션과 Luis의 한 줄짜리 jmh 벤치 마크입니다.

실행 중

sbt "jmh:run -i 10 -wi 10 -f 2 -t 1 bench.So59652263"

어디

@State(Scope.Benchmark)
@BenchmarkMode(Array(Mode.Throughput))
class So59652263 {
  def _dexter2305(number: Int): Int = {
    def helper(current: Int, accumulator: Int): Int = {
      current match {
        case current if current < 10 => accumulator * current
        case _ => helper(current / 10, accumulator * (current % 10))
      }
    }
    helper(number, 1)
  }

  def _luis(number: Int): Int = number.toString.map(_.asDigit).product

  val num: Int = (math.random * 100000000).toInt
  @Benchmark def dexter2305: Int = _dexter2305(num)
  @Benchmark def luis: Int = _luis(num)
}

준다

[info] So59652263.dexter2305  thrpt   20  89093066.408 ± 1825286.801  ops/s
[info] So59652263.luis        thrpt   20  11585098.230 ±  272966.526  ops/s

재귀 솔루션은 한 줄의 처리량보다 7 배 더 많은 처리량을 갖는 것으로 보입니다.

때 벤치마킹 number입니다 String대신Int

@State(Scope.Benchmark)
@BenchmarkMode(Array(Mode.Throughput))
class So59652263 {
  def _dexter2305(number: String): Int = {
    def helper(current: Int, accumulator: Int): Int = {
      current match {
        case current if current < 10 => accumulator * current
        case _ => helper(current / 10, accumulator * (current % 10))
      }
    }
    helper(number.toInt, 1)
  }

  def _luis(number: String): Int = number.map(_.asDigit).product

  val num: String = (math.random * 100000000).toInt.toString
  @Benchmark def dexter2305: Int = _dexter2305(num)
  @Benchmark def luis: Int = _luis(num)
}

준다

[info] Benchmark               Mode  Cnt         Score         Error  Units
[info] So59652263.dexter2305  thrpt   20  36237007.844 ± 1631349.975  ops/s
[info] So59652263.luis        thrpt   20  13975984.042 ± 1890083.941  ops/s

우리는 재귀 솔루션을 볼 경우 여전히 때보 다 2.5의 작은 배 그러나 높은 처리량,이 number되었다 Int.