Scala练习-基数排序

基数排序
源码

package day14import scala.collection.mutable.ArrayBuffer/**  * Created by doctorq on 2017/6/29.  * 基数排序  */object RadixSort extends Utils with App {  /*    获取数组中最大值   */  def max(unSort: Array[Int]): Int = {    if (unSort.size < 1) throw new IllegalArgumentException    var temp = unSort(0)    for (i <- 1 until unSort.size) {      if (unSort(i) > temp) {        temp = unSort(i)      }    }    temp  }  /**    * 获取数字的位数    *    * @param item    * @return    */  def getDigit(item: Int): Int = {    var digit = 1    var temp = item / 10    while (temp > 0) {      digit += 1      temp /= 10    }    digit  }  /**    * 获取数字在第index位上的值，123第二位的值2，第一位为3，第三位为1    *    * @param item    * @param index    * @return    */  def getNum(item: Int, index: Int): Int = {    if (index < 1) throw new IllegalArgumentException    //超出,自动补0    if (getDigit(item) < index) return 0    val itemStr = item.toString    itemStr.charAt(itemStr.size - index).toString.toInt  }  def generate(num: Int): Array[ArrayBuffer[Int]] = {    val bucket = new Array[ArrayBuffer[Int]](10)    for (i <- 0 until num) {      val temp = new ArrayBuffer[Int]()      bucket(i) = temp    }    bucket  }  /**    * 平铺二维数组到一维    *    * @param bucketArray    * @return    */  def flatten(bucketArray: Array[ArrayBuffer[Int]], size: Int): Array[Int] = {    val temp = new Array[Int](size)    var index = 0    for (i <- 0 until bucketArray.size) {      if (bucketArray(i).size != 0) {        for (j <- 0 until bucketArray(i).size if (bucketArray(i)(j) >= 0)) {          temp(index) = bucketArray(i)(j)          index += 1        }      }    }    temp  }  /**    *    * @param unSort 原始数组    * @param digit  最大数的位数    * @return 已排序好的数组    */  def sort(unSort: Array[Int], digit: Int): Array[Int] = {    var tempUnSort = unSort    for (i <- 1 to digit) {      val bucket = generate(10)      for (j <- 0 until tempUnSort.size) {        val index = getNum(tempUnSort(j), i)        bucket(index).append(tempUnSort(j))      }      tempUnSort = flatten(bucket, tempUnSort.size)    }    tempUnSort  }  val array = Array[Int](1, 45, 23, 0, 23, 234, 23, 5, 6, 7, 9, 9, 9, 456)  val digit = getDigit(max(array))  printlnArray(sort(array, digit))}