Time: 282 ms (14.06%), Space: 114 MB (81.72%) - LeetHub

Author: ComputerScientist-01

palindrome-linked-list/palindrome-linked-list.cpp

@@ -0,0 +1,47 @@
+/**
+ * Definition for singly-linked list.
+ * struct ListNode {
+ *     int val;
+ *     ListNode *next;
+ *     ListNode() : val(0), next(nullptr) {}
+ *     ListNode(int x) : val(x), next(nullptr) {}
+ *     ListNode(int x, ListNode *next) : val(x), next(next) {}
+ * };
+ */
+class Solution {
+public:
+    ListNode* reverse (ListNode* curr){
+        ListNode* cn=curr;
+        ListNode* prev= nullptr;    
+        while(curr != NULL){
+        cn=curr->next;
+            curr->next=prev;
+            prev=curr;
+            curr=cn;
+            
+        }
+        return prev;
+        
+    }
+    
+    bool isPalindrome(ListNode* head) {
+        if(head->next== NULL) return head;
+        ListNode *fast=head, *slow= head;
+        while(fast != nullptr and fast ->next != nullptr){
+            fast=fast->next->next;
+            slow=slow->next;
+        }
+        slow=reverse(slow);
+        fast=head;
+        
+        while(slow != nullptr)
+        {
+            if(slow->val != fast->val){
+                return false;
+            }
+            slow=slow->next;
+            fast=fast->next;
+        }
+        return true;
+    }
+};