快速排序

Posted 2020-07-16

快速排序

public class QuickSort {

    public static  int getMiddle(int[] list, int low, int high){
        int tmp = list[low];    //数组的第一个作为中轴
        while (low < high) {
            while (low < high && list[high] >= tmp) {
                high--;
            }
            list[low] = list[high];   //比中轴小的记录移到低端
            while (low < high && list[low] <= tmp) {
                low++;
            }
            list[high] = list[low];   //比中轴大的记录移到高端
        }
        list[low] = tmp;              //中轴记录到尾
        return low;                   //返回中轴的位置
    }
    public static void quickSort(int[] list, int low, int high){
        if (low < high) {
            int middle = getMiddle(list, low, high);  //将list数组进行一分为二
            System.out.println(Arrays.toString(list));
            quickSort(list, low, middle - 1);        //对低字表进行递归排序
            quickSort(list, middle + 1, high);       //对高字表进行递归排序

        }
    }

    public static  void quick(int[] arr) {
        if (arr.length > 0) {    //查看数组是否为空
            quickSort(arr, 0, arr.length - 1);
        }
    }

    public static void main(String[] args) {
        int a[]={49,38,65,97,76,13,27,49,78,34,12,64,5,4,62,99,98,54,56,17,18,23,34,15,35,25,53,51};
        quick(a);
    }

}