Backreferences problems

Author: imKashyap

Hackerrank/Regex/Backrefrences/BackrefToFailedGrps.java

@@ -0,0 +1,28 @@
+import java.io.*;
+import java.util.*;
+import java.text.*;
+import java.math.*;
+import java.util.regex.*;
+
+public class Solution {    
+
+    public static void main(String[] args) {
+        
+        Regex_Test tester = new Regex_Test();
+        tester.checker("^\\d{2}(-?)\\d{2}\\1\\d{2}\\1\\d{2}$"); // Use \\ instead of using \ 
+    
+    }
+}
+
+class Regex_Test {
+
+    public void checker(String Regex_Pattern){
+    
+        Scanner Input = new Scanner(System.in);
+        String Test_String = Input.nextLine();
+        Pattern p = Pattern.compile(Regex_Pattern);
+        Matcher m = p.matcher(Test_String);
+        System.out.println(m.find());
+    }   
+    
+}

Hackerrank/Regex/Backrefrences/BranchResetGrps.php

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+<?php
+
+$Regex_Pattern = '/^\d{2}(---|-|.|:)\d{2}\1\d{2}\1\d{2}$/'; //Do not delete '/'. Replace __________ with your regex.
+
+$handle = fopen ("php://stdin","r");
+$Test_String = fgets($handle);
+if(preg_match($Regex_Pattern, $Test_String, $output_array)){
+    print ("true");
+} else {
+    print ("false");
+}
+
+fclose($handle);
+?>

Hackerrank/Regex/Backrefrences/ForwardRefs.php

@@ -0,0 +1,14 @@
+<?php
+
+$Regex_Pattern = '/^(\2tic|(tac))+$/'; //Do not delete '/'. Replace __________ with your regex.
+
+$handle = fopen ("php://stdin","r");
+$Test_String = fgets($handle);
+if(preg_match($Regex_Pattern, $Test_String, $output_array)){
+    print ("true");
+} else {
+    print ("false");
+}
+
+fclose($handle);
+?>

Hackerrank/Regex/Backrefrences/MatchingSameText.java

@@ -0,0 +1,28 @@
+import java.io.*;
+import java.util.*;
+import java.text.*;
+import java.math.*;
+import java.util.regex.*;
+
+public class Solution {    
+
+    public static void main(String[] args) {
+        
+        Regex_Test tester = new Regex_Test();
+        tester.checker("^([a-z]\\w\\s\\W\\d\\D[A-Z][a-zA-Z][aeiouAEIOU]\\S)\\1$"); // Use \\ instead of using \ 
+    
+    }
+}
+
+class Regex_Test {
+
+    public void checker(String Regex_Pattern){
+    
+        Scanner Input = new Scanner(System.in);
+        String Test_String = Input.nextLine();
+        Pattern p = Pattern.compile(Regex_Pattern);
+        Matcher m = p.matcher(Test_String);
+        System.out.println(m.find());
+    }   
+    
+}