Java:算法:三向切分快速排序

Posted 2021-05-11 K Depth

package com.unit2.quicksort;/** * 三向切分的快速排序 * * @author Kou * date 2021/3/27 */
import java.util.Scanner;
public class Quick { private static void quicksort(Comparable[] arr) { sort(arr, 0, arr.length - 1); }
 private static void sort(Comparable[] arr, int lo, int hi) { if (lo >= hi) { //基准条件 return; } int lt = lo, i = lo + 1, gt = hi; //lt一直指向基准值，i为当前遍历元素 Comparable v = arr[lo]; while (i <= gt) { //递归条件 int cmp = arr[i].compareTo(v); if (cmp < 0) { //当前指向元素小于基准值 exch(arr, lt++, i++); } else if (cmp > 0) { //当前指向元素大于基准值 exch(arr, i, gt--); } else { //当前指向元素与基准值相等 i++; } } //递归 sort(arr, lo, lt - 1); sort(arr, gt + 1, hi); }
 private static void exch(Comparable[] a, int i, int j) { //交换元素 Comparable t = a[i]; a[i] = a[j]; a[j] = t; }
 private static void show(Comparable[] arr) { for (Comparable i : arr) { System.out.print(i + " "); } }
 public static void main(String[] args) { Scanner in = new Scanner(System.in); Comparable[] arr = new Comparable[10]; for (int i = 0; i < arr.length; i++) { arr[i] = in.nextInt(); } quicksort(arr); show(arr); }}