自然数加密解密

规则:对自然数的每位数加6后再对10求余,最后反转数字顺序

备注:当数字前加0,如0012,代码不成立,仍需改进

public class Demo1 {
    public static void main(String[] args) {
        int num = 444;
        String s = String.valueOf(num);
        s = encrypt(s);//加密
        System.out.println(String.valueOf(s));
        num = decryption(s);//解密
        System.out.println(num);
    }

    public static String encrypt(String s) {
        int[] arr = new int[s.length()];
        char[] chars = s.toCharArray();

        for (int i = 0; i < chars.length; i++) {
            arr[i] = (chars[i] - '0' + 6) % 10;
        }
        s = "";
        for (int i = 0, j = arr.length - 1; i < j; i++, j--) {
            int tem = arr[i];
            arr[i] = arr[j];
            arr[j] = tem;
        }

        for (int c : arr) {
            s += c;
        }

        return String.valueOf(s);
    }

    public static int decryption(String s) {

        int[] arr = new int[s.length()];
        char[] chars = s.toCharArray();

        for (int i = 0; i < chars.length; i++) {
            arr[i] = (chars[i] - '0' + 4) % 10;
        }
        s = "";
        for (int i = 0, j = arr.length - 1; i < j; i++, j--) {
            int tem = arr[i];
            arr[i] = arr[j];
            arr[j] = tem;
        }

        for (int c : arr) {
            s += c;
        }

        return Integer.parseInt(s);

    }

}