题解 | #整数与IP地址间的转换#--字符串+数组操作

import java.util.*;

public class Main {
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        while (in.hasNextLine()) {
            String[] strs = in.nextLine().split("\\.");
            long decNum = Long.parseLong(in.nextLine());
            // ip转化为整数
            StringBuffer sb = new StringBuffer();
            for (String str : strs) {
                int tem = Integer.parseInt(str);
                sb.append(String.format("%8s", Integer.toBinaryString(tem)).replace(" ", "0"));
            }
            System.out.println(getInteger(sb.toString()));
            // 整数转ip
            String binaryStr = String.format("%32s",
                                             Long.toBinaryString(decNum)).replace(" ", "0");
            StringBuffer bf = new StringBuffer();
            for (int i = 0; i < binaryStr.length() / 8; i++) {
                bf.append(getInteger(binaryStr.substring(8 * i, 8 * (i + 1))) + ".");
            }
            System.out.println(bf.toString().substring(0, bf.length() - 1));
        }
    }

    private static long getInteger(String binaryStr) {
        long res = 0;
        char[] chrs = binaryStr.toCharArray();
        for (int i = chrs.length - 1; i >= 0; i--) {
            if (chrs[i] == '1') {
                res += Math.pow(2, binaryStr.length() - 1 - i);
            }
        }
        return res;
    }
}