判断两个IP是否属于同一子网

package com.oj;

import java.util.Scanner;


public class TestOj {
	public static void main(String[] args) {
		Scanner in = new Scanner(System.in);
		//String input = in.nextLine();
		String[] data = new String[3];
		data[0] = in.nextLine();
		data[1] = in.nextLine();
		data[2] = in.nextLine();
		if(data.length!=3){
			System.out.println("1");
			return ;
		}
		String[] masks = data[0].split("\\.");
		String[] ips = data[1].split("\\.");
		String[] ips2 = data[2].split("\\.");
		
		if(masks.length!=4||ips.length!=4||ips2.length!=4){
			System.out.println("1");
			return ;
		}
		
		int[] mask = new int[4];
		int[] ip = new int[4];
		int[] ip2 = new int[4];
		for(int i = 0;i < 4; i++){
			try{
				mask[i] = Integer.parseInt(masks[i]);
				ip[i] = Integer.parseInt(ips[i]);
				ip2[i] = Integer.parseInt(ips2[i]);
				if(mask[i]<0&&mask[i]>255){
					System.out.println("1");
					return;
				}
				
				if(ip[i]<0&&ip[i]>255){
					System.out.println("1");
					return;
				}
				
				if(ip2[i]>0&&ip2[i]>255){
					System.out.println("1");
					return;
				}
			}catch(Exception e){
				System.out.println("1");
				return;
			}
		}
		
		
		
		StringBuilder masksb = new StringBuilder();
		StringBuilder ipsb = new StringBuilder();
		StringBuilder ipsb2 = new StringBuilder();
		for(int i = 0;i < 4; i++){
			String temp = Integer.toBinaryString(mask[i]);
			if(temp.length()!=8)
				for(int j = 0;j < 8-temp.length(); j++)
					masksb.append("0");
			masksb.append(temp);
			
			String temp2 = Integer.toBinaryString(ip[i]);
			if(temp2.length()!=8)
				for(int j = 0;j < 8-temp2.length(); j++)
					ipsb.append("0");
			ipsb.append(temp2);
			//System.out.println("ipsb: "+ipsb.toString());
			
			String temp3 = Integer.toBinaryString(ip2[i]);
			if(temp3.length()!=8)
				for(int j = 0;j < 8-temp3.length(); j++)
					ipsb2.append("0");
			ipsb2.append(temp3);
		}
		StringBuilder a = new StringBuilder();
		for(int i = 0;i < masksb.toString().length(); i++)
			if(masksb.charAt(i)==‘1‘&&ipsb.charAt(i)==‘1‘)
				a.append("1");
			else
				a.append("0");
		
		StringBuilder b = new StringBuilder();
		for(int i = 0;i < masksb.toString().length(); i++)
			if(masksb.charAt(i)==‘1‘&&ipsb2.charAt(i)==‘1‘)
				b.append("1");
			else
				b.append("0");
		
		if(a.toString().equals(b.toString()))
			System.out.println("0");
		else
			System.out.println("2");
	}
}