@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; } } }