Optimized approach for palindrome linked list

Author: Nandini-Pandey

src/main/java/com/thealgorithms/misc/PalindromeSinglyLinkedList.java

@@ -30,4 +30,46 @@ public static boolean isPalindrome(final SinglyLinkedList linkedList) {
 
         return true;
     }
+
+    public static boolean isPalindromeOptimised(Node head){
+        if(head==null || head.next==null){
+           return true;
+        }
+        Node slow= head;
+        Node fast=head;
+        while(fast!=null && fast.next!=null){
+           slow=slow.next;
+           fast=fast.next.next;
+        }
+        Node midNode= slow;
+
+        Node prevNode=null;
+        Node currNode=midNode;
+        Node nextNode;
+        while(currNode!=null){
+           nextNode=currNode.next;
+           currNode.next=prevNode;
+           prevNode=currNode;
+           currNode=nextNode;
+        }
+        Node left=head;
+        Node right=prevNode;
+        while(left!=null && right!=null){
+           if(left.val!=right.val){
+               return false;
+           }
+           right=right.next;
+           left=left.next;
+        }
+        return true;
+       
+    }
+    static class Node{
+        int val;
+        Node next;
+        public Node(int val) {
+            this.val = val;
+            this.next = null;
+        }
+    }
 }