判断两个IP是否属于同一子网

import java.util.*;
public class Main {
        public static void mian(String[] args){
            Scanner sc = new Scanner(System.in);
            int[] ip1AfterHex = new int[4];
            int[] ip2AfterHex = new int[4];
            int[] subnetAfterHex = new int[4];
            while(sc.hasNext()){
                String subnetMask = sc.nextLine();
                String ip1 = sc.nextLine();
                String ip2 = sc.nextLine();
                String[] subnetArray = subnetMask.split("\\.");
                String[] ip1Array = ip1.split("\\.");
                String[] ip2Array = ip2.split("\\.");
                for(int i=0;i<4;i++){
                    String xs = Integer.toBinaryString(Integer.parseInt(ip1Array[i]));
                    String ys = Integer.toBinaryString(Integer.parseInt(ip2Array[i]));
                    String zs = Integer.toBinaryString(Integer.parseInt(subnetArray[i]));
                    ip1AfterHex[i]=Integer.parseInt(xs);
                    ip2AfterHex[i]=Integer.parseInt(ys);
                    subnetAfterHex[i]=Integer.parseInt(zs);
                }
                if(!isIp(ip1AfterHex)||!isIp(ip2AfterHex)||!isAd(subnetAfterHex)){
                System.out.println(1);
                continue;
                }
            boolean flag=true;
            for(int i=0;i<4;i++){
               if((ip1AfterHex[i]&subnetAfterHex[i])!=(ip2AfterHex[i]&subnetAfterHex[i])){
                    System.out.println(2);
                    flag=false;
                    break;
                }
            }
            if(flag)
                System.out.println(0);


            }
        }
        public static boolean isAd(int[] a){
        return a[0]>=0&&a[0]<=255&&
                a[1]>=0&&a[1]<=255&&
                a[2]>=0&&a[2]<=255&&
                a[3]>=0&&a[3]<=255&&
                a[0]>=a[1]&&
                a[1]>=a[2]&&
                a[2]>=a[3];
        }

        public static boolean isIp(int[] a){
        return a[0]>=0&&a[0]<=255&&
                a[1]>=0&&a[1]<=255&&
                a[2]>=0&&a[2]<=255&&
                a[3]>=0&&a[3]<=255;
        }
}