scala示例

ScalaExample.scala

package t1

object Just {

  def main(arg : Array[String]) : Unit = {
    val a = new Array[Int](10)

    val x = Array(6, 23, 123, 5563, 345, 11);

    quicksort(x) foreach println
    
    mergesort(_>_)(x.toList) foreach println
    
  }

  def quicksort(args : Array[Int]) : Array[Int] = {
    if (args.size <= 1)
      args
    else {
      val m = args(args.length >>> 1)
      Array.concat(
        quicksort(args.filter(m >)),
        quicksort(args.filter(m ==)),
        quicksort(args.filter(m <)))
    }
  }

  def mergesort(compare : (Int, Int) => Boolean)(col : List[Int]) : List[Int] = {
    def merge(col1 : List[Int], col2 : List[Int]) : List[Int] = {
    	if(col1.isEmpty) col2
    	else if(col2.isEmpty) col1
    	else if(compare(col1.head,col2.head)) col1.head :: merge(col1.tail,col2)
    	else col2.head :: merge(col1,col2.tail)
    }
    
    val n = col.length >>> 1
    if(n == 0) col
    else merge(mergesort(compare)(col.take(n)),mergesort(compare)(col.drop(n)))
    
  }

}