题解 | #整数与IP地址间的转换#

import java.util.Scanner;

// 注意类名必须为 Main, 不要有任何 package xxx 信息
public class Main {
    public static long ipToLong(String ipAddress) {
        String[] ipAddressInArray = ipAddress.split("\\.");
        long result = 0;
        for (int i = 0; i < 4; i++) {
            int octet = Integer.parseInt(ipAddressInArray[i]);
            result += ((long) octet & 0xFF) << (8 * (3 - i));
        }
        return result;
    }

    public static String LongToIp(long longValue) {
        StringBuilder ipAddress = new StringBuilder();
        for (int i = 3; i >= 0; i--) {
            int octet = (int) ((longValue >> (8 * i)) & 0xFF);
            ipAddress.append(octet);
            if (i > 0) {
                ipAddress.append(".");
            }
        }
        return ipAddress.toString();

    }


    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        String ipAddress =  sc.nextLine();
        Long longValue2 =  Long.valueOf(sc.nextLine());
        System.out.println(ipToLong(ipAddress));
        System.out.println(LongToIp(longValue2));
        
    }
}