Create Palindrome.java

Author: Chakravartii

src/main/java/com/thealgorithms/recursion/Palindrome.java

@@ -0,0 +1,28 @@
+package com.thealgorithms.recursion;
+
+/*
+    Check if a string is a palindrome using recursion.
+    Example: "madam" → true, "hello" → false
+*/
+public final class Palindrome {
+    private Palindrome() {
+        throw new UnsupportedOperationException("Utility class");
+    }
+
+    public static boolean isPalindrome(String str) {
+        if (str == null) {
+            throw new IllegalArgumentException("Null string not allowed");
+        }
+        return isPalindromeHelper(str, 0, str.length() - 1);
+    }
+
+    private static boolean isPalindromeHelper(String str, int left, int right) {
+        if (left >= right) {
+            return true;
+        }
+        if (str.charAt(left) != str.charAt(right)) {
+            return false;
+        }
+        return isPalindromeHelper(str, left + 1, right - 1);
+    }
+}