scala 排序算法 归并排序

scala 排序算法 归并排序 

归并（Merge）排序法是将两个（或两个以上）有序表合并成一个新的有

序表，即把待排序序列分为若干个子序列，每个子序列是有序的。然后再把有序子序列合并

为整体有序序列。

package com.xing.hai

/**
  * Created by xxxx on 3/1/2017.
  * 49 38 65 97 76 13 27 49 78 34 12 64 5 4 62 99 98 54 56 17 18 23 34 15 35 25 53 51
  * 4 5 12 13 15 17 18 23 25 27 34 34 35 38 49 49 51 53 54 56 62 64 65 76 78 97 98 99
  */
object OrderMergeSort extends  App{

  val arrayData = Array(49,38,65,97,76,13,27,49,78,34,12,64,5,4,62,99,98,54,56,17,18,23,34,15,35,25,53,51)
  arrayData.foreach(x => print(x + " "))
  splitDataAndSort(arrayData,0,arrayData.length -1)
  println
  arrayData.foreach(x => print(x + " "))

  def splitDataAndSort(arrayData:Array[Int],left:Int,right :Int): Unit ={
    if (left<right){
      val  center = (left+right)/2
      //println(center)
      splitDataAndSort(arrayData,left,center)
      splitDataAndSort(arrayData,center+1 ,right)
      splitedSort(arrayData,left,center,right)
    }
  }
  def splitedSort(arrayData:Array[Int],left:Int,center:Int ,right :Int): Unit ={
    val tempArray = new Array[Int](arrayData.length.toInt)
    var pointOfTemparray = left
    var leftx = left
    var midOfright = center + 1
    while(leftx <= center && midOfright<= right){
      if (arrayData(leftx)< arrayData(midOfright)){
        tempArray(pointOfTemparray) = arrayData(leftx)
        pointOfTemparray +=1
        leftx += 1
      }else{
        tempArray(pointOfTemparray) = arrayData(midOfright)
        pointOfTemparray +=1
        midOfright += 1
      }
    }
    while(leftx <= center){
      tempArray(pointOfTemparray) = arrayData(leftx)
      pointOfTemparray +=1
      leftx += 1
    }
    while(midOfright<= right){
      tempArray(pointOfTemparray) = arrayData(midOfright)
      pointOfTemparray +=1
      midOfright += 1
    }
    var copyDataBack = left
    while (copyDataBack<=right){
      arrayData(copyDataBack) = tempArray(copyDataBack)
      copyDataBack +=1
    }
  }
}