高级排序--希尔排序

排序原理：

1.选定一个增长量h，按照增长量h作为数据分组的依据，对数据进行分组；

2.对分好组的每一组数据完成插入排序；

3.减小增长量，最小减为1，重复第二步操作。

排序过程:

例:{9,1,2,5,7,4,8,6,3,5}

package com.sort;
/*--------------
 *  Author:Real_Q
 *  Date:2021-01-06
 *  Time:18:43
 *  Description:
 * {9,1,2,5,7,4,8,6,3,5}
 * {1,2,3,4,5,5,6,7,8,9}
---------------*/
public class ShellSort {
    //排序
    public static void shellSort(Comparable[] comparables) {

        //求增长量h
        int h = 1;
        int length = comparables.length;
        while (h < length / 2) {
            h = (h * 2 + 1);
        }
        //算法实体,当h大于等于一时,循环算法
        while (h >= 1) {
            //希尔排序规律,每次从h开始
            for (int i = h; i < length; i++) {
                //从i开始,倒叙遍历,比较后满足条件交换,条件不满足时,退出循环,进入下一次的循环
                for (int j = i; j >= h; j -= h) {
                    if (Comparable(comparables[j - h], comparables[j])) {
                        exchange(comparables, j - h, j);
                    } else {
                        break;
                    }
                }
            }
            //减小增长量
            h /= 2;
        }
    }
    //比较两个元素的大小
    public static boolean Comparable(Comparable comparable1, Comparable comparable2) {
        return comparable1.compareTo(comparable2) > 0;
    }

    //交换元素
    public static void exchange(Comparable[] comparable, int leftIndex, int rightIndex) {
        Comparable temp;
        temp = comparable[leftIndex];
        comparable[leftIndex] = comparable[rightIndex];
        comparable[rightIndex] = temp;
    }
}

测试类:

package com.testsort;
/*--------------
 *  Author:Real_Q
 *  Date:2021-01-06
 *  Time:19:05
 *  Description:
 * {9,1,2,5,7,4,8,6,3,5}
 * {1,2,3,4,5,5,6,7,8,9}
---------------*/

import java.util.Arrays;

import static com.sort.ShellSort.shellSort;

public class TestShell {
    public static void main(String[] args) {
        Integer[] array = {4,6,8,7,9,2,10,1};
        shellSort(array);
        System.out.println(Arrays.toString(array));
    }
}