快排

package com.lxw.demo;

import java.util.Arrays;

public class kuaipai {

    private static int count;

    public static void main(String[] args) {
        int[] num = {3,45,78,64,52,11,64,55,99,11,18};
        System.out.println("未排序"+Arrays.toString(num));
        QuickSort(num,0,num.length-1);
        System.out.println("排序"+Arrays.toString(num));
        System.out.println("数组长度："+num.length);
        System.out.println("循环次数："+count);


    }

    private static void QuickSort(int[] num, int left, int right) {
        //如果left等于right，即数组只有一个元素，直接返回
        if(left>=right) {
            return;
        }
        //设置最左边的元素为基准值
        int key=num[left];
        //数组中比key小的放在左边，比key大的放在右边，key值下标为i
        int i=left;
        int j=right;
        while(i<j){
            //j向左移，直到遇到比key小的值
            while(num[j]>=key && i<j){
                j--;
            }
            //i向右移，直到遇到比key大的值
            while(num[i]<=key && i<j){
                i++;
            }
            //i和j指向的元素交换
            if(i<j){
                int temp=num[i];
                num[i]=num[j];
                num[j]=temp;
            }
        }
        num[left]=num[i];
        num[i]=key;
        count++;
        QuickSort(num,left,i-1);
        QuickSort(num,i+1,right);
    }


}