JAVA常见算法题(三十四)---计算加密之后的电话号码

public static void main(String[] args) {
            f(2345);
        }

        public static void f(int num) {
            int[] c = new int[4];
            if (num > 999 && num < 10000) {
                c[0] = num / 1000;
                c[1] = (num / 100) % 10;
                c[2] = (num / 10) % 10;
                c[3] = num % 10;
                for (int j = 0; j < 4; j++) {
                    c[j] += 5;
                    c[j] %= 10;
                }
                for (int j = 0; j <= 1; j++) {
                    int temp = c[j];
                    c[j] = c[3 - j];
                    c[3 - j] = temp;
                }
                System.out.print("加密后的数字为：");
                for (int j = 0; j < 4; j++)
                    System.out.print(c[j]);
            } else {
                System.out.println("传输的数据有错，请重试！！！");
            }
        }