@Test
    public void test11() {
        String str = "abc";
        test11_01(str.toCharArray(), 0);
    }

    public void test11_01(char[] str, int i) {
        if (i > str.length) {
            return;
        } else if (i == str.length - 1) {
            System.out.println(Arrays.toString(str));
        } else {
            for (int j = i; j < str.length; j++) {

                char temp = str[j];
                str[j] = str[i];
                str[i] = temp;


                test11_01(str, i + 1);

                temp = str[j];
                str[j] = str[i];
                str[i] = temp;

            }
        }

    }