Problem Difficulty Level: Easy

Author: Naganathan05

Linked List/234. Palindrome Linked List.cpp

@@ -0,0 +1,46 @@
+/*------------------------
+  Time Complexity: O(n)
+  Space Complexity: O(1)
+--------------------------*/
+
+class Solution {
+public:
+    ListNode* reverse(ListNode* head){
+        ListNode* prev = NULL;
+        ListNode* curr = head;
+        while(curr){
+            ListNode* nex = curr -> next;
+            curr -> next = prev;
+            prev = curr;
+            curr = nex;
+        }
+        return prev;
+    }
+
+    bool isPalindrome(ListNode* head) {
+
+        if(head == NULL || head -> next == NULL){
+            return true;
+        }
+
+        ListNode* fast = head;
+        ListNode* slow = head;
+        while(fast && fast -> next){
+            slow = slow -> next;
+            fast = (fast -> next) -> next;
+        }
+
+        ListNode* reversedList = reverse(slow);
+        while(reversedList){
+            if(head -> val != reversedList -> val) return false;
+            head = head -> next;
+            reversedList = reversedList -> next;
+        }
+        return true;
+    }
+};
+
+/*
+Question Link: https://leetcode.com/problems/palindrome-linked-list/
+Author: M.R.Naganathan
+*/