递归解决回文判断

思路，主体方法调用递归，比较首位是否相同，相同则消再递归掉比较，代码逻辑清晰，待优化。

    public static void receiveString(String s) {
        if (s.length() == 1 || s.length() == 0) {
            System.out.println("yes");
            return;
        } else if (isOK(s)) {
            receiveString(toShort(s));
        } else {
            System.out.println("no");
        }
    }

    private static boolean isOK(String s) {
        char[] ch = s.toCharArray();
        return ch[0] == ch[ch.length - 1];
    }

    private static String toShort(String s) {
        char[] ch = s.toCharArray();
        char[] ch2 = new char[ch.length - 2];
        int i = 0;
        for (int j = 1; j < ch.length - 1; j++) {
            ch2[i] = ch[j];
            i++;
        }
        return new String(ch2);
    }