In this HackerRank Java Regex problem, you need to write a regular expression and assign it to the pattern such that it can be used to validate an IP address.

HackerRank Java Regex problem solution

HackerRank Java Regex problem solution

import java.util.regex.Matcher;
import java.util.regex.Pattern;
import java.util.Scanner;

class Solution{

    public static void main(String []args)
    {
        Scanner in = new Scanner(System.in);
        while(in.hasNext())
        {
            String IP = in.next();
            System.out.println(IP.matches(new MyRegex().pattern));
        }

    }
}

//YOU SHOULD ONLY SUBMIT THE FOLLOWING BLOCK
class MyRegex
{
         String pattern = 
            "^([01]?\\d\\d?|2[0-4]\\d|25[0-5])\\." +
            "([01]?\\d\\d?|2[0-4]\\d|25[0-5])\\." +
            "([01]?\\d\\d?|2[0-4]\\d|25[0-5])\\." +
            "([01]?\\d\\d?|2[0-4]\\d|25[0-5])$";

}