题解 | #整数与IP地址间的转换#

不知道为什么这道题必须要用Long才行

import java.util.*;
public class Main{
    public static void main(String[] args){
        Scanner scan = new Scanner(System.in);
        while(scan.hasNext()){
            String str = scan.nextLine();
            String[] strs = str.split("\\.");
            StringBuilder strb = new StringBuilder();
            for(String s : strs){
                s = Integer.toString(Integer.parseInt(s) ,2);
                while(s.length()<8){
                    s = "0"+s;
                }
                strb.append(s);
            }
            Long n = Long.parseLong(strb.toString(),2);
            System.out.println(n);
            
            String s1 = scan.nextLine();
//             String s2 = Integer.toString(Integer.parseInt(s1) ,2);
            String s2 = Long.toString(Long.parseLong(s1),2);
            while(s2.length()<32){
                s2 = "0"+s2;
            }
            int[] nums = new int[s2.length()/8];
            for(int i = 0; i<s2.length()/8; i++){
                nums[i] = Integer.parseInt(s2.substring(8*i, 8*i+8),2);
                
            }
            for(int i = 0; i<nums.length-1; i++){
                System.out.print(nums[i]+".");
            }
            System.out.print(nums[nums.length-1]);
        }
        scan.close();
    }
}