Using pattern and matcher

using [] and (), |

Author: Kingbond470

RegexProblem.java

@@ -0,0 +1,36 @@
+/*
+https://www.hackerrank.com/challenges/java-regex/problem
+*/
+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));
+        }
+
+    }
+}
+
+//Write your code here
+class MyRegex{
+    
+    /*
+    matcher-- used to search the pattern
+    pattern-  to be used in search
+    0-9--> [0-9]                        // [0-9] any value range from 0 to 9
+    09-99 --> [0-9][0-9]  ......bocz leading zero is allowed
+    099-199 --> (0|1)[0-9][0-9]             // (0|1) choose either 0 or 1
+    200-249--> 2 [0-4][0-9]
+    250-254 --> 25 [0-4]
+    */
+     String value="([0-9]|[0-9][0-9]|(0|1)[0-9][0-9]|2[0-4][0-9]|25[0-5])";
+     
+     String pattern=value+"."+value+"."+value+"."+value;
+     
+}