题解 | #整数与IP地址间的转换#

import java.util.*;

public class Main {
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        String[] ip = new String(in.nextLine()).split("\\.");
        long n = in.nextLong();

        //ip转数
        String b1 = "";
        for (int i = 0; i < 4; i++) {
            String binary = new String(Integer.toBinaryString(Integer.parseInt(ip[i]))); //10进制转2进制序列

            //不满8位补0
            int len = binary.length();
            for (int j = 0; j < 8 - len; j++)binary = "0" + binary;

            b1 += binary; //拼接
        }
        System.out.println(Long.parseLong(b1, 2));

        //数转ip
        String  b2 = new String(Long.toBinaryString(n)); //转2进制串
        //不满32位补零
        int len = b2.length();
        for (int i = 0; i < 32 - len; i++) {
            b2 = "0" + b2;
        }

        int[] ipNum = new int[4];
        for (int i = 0; i < 4; i++) {
            ipNum[i] = Integer.parseInt(b2.substring(i * 8, i * 8 + 8), 2);//2进制转10进制
            if (i < 3)System.out.print(ipNum[i] + ".");
            else System.out.print(ipNum[i]);
        }



    }
}