快速排序

此方法学习了别人的算法，感觉清晰明了了很多。

package sort;

public class quickSortDemo {

    public static void main(String[] args) {
        int[] arr = new int[]{101, 34, 119, 1, 52, 38, 67, 96, 23, 15, 2, 111};
        quickSort(arr, 0, arr.length - 1);
        for (int i : arr) {
            System.out.print(i+",");
        }
        System.out.println();
    }

    private static void quickSort(int[] arr, int low, int high) {
        if (low < high) {
            //找寻基准数据的正确索引
            int index = getIndex(arr, low, high);

            quickSort(arr, low, index - 1);
            quickSort(arr, index + 1, high);
        }
    }

    private static int getIndex(int[] arr, int low, int high) {
        //基准数据
        int temp = arr[low];
        while (low < high) {
            //当队尾的元素大于等于基准数据时，向前挪动high指针
            while (arr[high] >= temp && low < high) {
                high--;
            }
            //如果队尾元素小于tmp,需要将其赋值给low
            arr[low] = arr[high];

            //当队首的元素小于等于基准数据时，向后挪动high指针
            while (arr[low] <= temp && low < high) {
                low++;
            }
            //如果队尾元素小于tmp,需要将其赋值给low
            arr[high] = arr[low];
        }
        //跳出循环时，low和high相等，此时的low或者high就是tmp的正确索引位置
        //但是此时的Low的位置的值并不是tmp,所以需要将tmp赋值给arr。
        arr[low] = temp;
        return low;
    }
}

参考的文章链接：https://blog.csdn.net/nrsc272420199/article/details/82587933
https://wiki.jikexueyuan.com/project/easy-learn-algorithm/fast-sort.html