java 快速排序算法

    int[] a = {3,2,5,4,6,7,8,9,2,0,5,3,1,6,7,8,4,3};
    //按从小到大排序
    public static void quickSort(int[] a, int start, int end) {
        if (start < end) {
            int i = start, j = end;
            int temp = a[start];
            while (i < j) {
                while (i < j && a[j] >= temp) {
                    j--;
                }
                a[i] = a[j];

                while (i < j && a[i] <= temp) {
                    i++;
                }
                a[j] = a[i];
            }
            a[i] = temp;                              //到这里说明i==j，所以无论用a[i]或者a[j]都是一样的
            quickSort(a, start, i - 1);
            quickSort(a, i + 1, end);
        }
    }