Scala练习-堆排序

源码地址

package day14import scala.collection.mutable.ArrayBuffer/**  * Created by doctorq on 2017/6/19.  * 堆排序：采用大顶堆,根节点大于两层元素，该类需要满足具备三个方法: 1.由正常数组变换为符合堆结构的方法  * 2.向堆中插入数据。3.从堆中删除数据。  * 重要特性：1.根节点索引值为i，根节点元素满足Key[i]>=Key[2i+1]&&key>=key[2i+2]  * 2.非叶子节点数量<=总节点数的/2  */object HeapSort extends App {  /**    * 生成对结构    *    * @param unSortHeap 任意数组    * @return 符合堆结构的数组    */  def generateHeap(unSortHeap: Array[Int]): Array[Int] = {    val num = unSortHeap.length    if (num <= 1) return unSortHeap    var tempUnSortHeap = unSortHeap    for (i <- num / 2 - 1 until num) {      tempUnSortHeap = sort(tempUnSortHeap, i)    }    tempUnSortHeap  }  /**    * 排序特定子树    *    * @param heap  未排序堆    * @param index 当前排序索引值    * @return 某子树已经排序完    */  def sort(heap: Array[Int], index: Int): Array[Int] = {    //父节点    var childIndex = index    var parentIndex = (childIndex - 1) / 2    var temp = heap(childIndex)    while (parentIndex >= 0 && childIndex != 0) {      if (heap(parentIndex) < temp) {        //swap        heap(childIndex) = heap(parentIndex)        heap(parentIndex) = temp      }      childIndex = parentIndex      parentIndex = (childIndex - 1) / 2      temp = heap(childIndex)    }    heap  }  /**    * 从堆中删除数据    *    * @param sortedHeap 已排序的队列    * @param index      索引值    */  def deleteFromHeap(sortedHeap: Array[Int], index: Int): Array[Int] = {    val newArray = sortedHeap.toBuffer    newArray.remove(index)    generateHeap(newArray.toArray)  }  /**    * 向堆中插入数据    *    * @param sortedHeap 已排序的队列    * @param newElement 添加到对中的元素    */  def insertToHeap(sortedHeap: Array[Int], newElement: Int): Array[Int] = {    val newList = sortedHeap :+ newElement    sort(newList, newList.length - 1)  }  def printlnList(sortedHeap: Array[Int]): Unit = {    sortedHeap.foreach(item => print(s"$item "))    println("sorted!")    //    for (k <- sortedHeap.indices) {    //      println(s"($k->${sortedHeap(k)})")    //    }  }  private def sortAll = {    while (sortedList.length > 0) {      print(s"${sortedList.head} ")      sortedList = generateHeap(sortedList.tail)      //    printlnList(sortedList)    }  }  val list = Array[Int](1, 4, 3, 5, 6, 8, 2, 3, 89, 4, 34, 50)  var sortedList = generateHeap(list)  printlnList(sortedList)  //添加新元素  printlnList(insertToHeap(sortedList, 76))  //删除  printlnList(deleteFromHeap(sortedList, 3))  //堆排序,按大到小输出元素  sortAll}