1.     /**
    2.      * @Description: 交换数组中的两个值
    3.      * @Auther: lizhouwei
    4.      * @Date: 2018/6/23 8:33
    5.      * @Modified By:
    6.      */
    7.     public static void swap(Integer[] arr, int a, int b) {
    8.         if (a == b) return;
    9.         arr[a] = arr[a] ^ arr[b];
    10.         arr[b] = arr[a] ^ arr[b];
    11.         arr[a] = arr[a] ^ arr[b];
    12.     }