Palindrome Linked List

 1 /**
 2  * Definition for singly-linked list.
 3  * struct ListNode {
 4  *     int val;
 5  *     ListNode *next;
 6  *     ListNode(int x) : val(x), next(NULL) {}
 7  * };
 8  */
 9 class Solution {
10 public:
11     bool isPalindrome(ListNode* head) {
12         if(!head || !head->next) return true;
13         
14         vector<int> v;
15         while(head){
16             v.push_back(head->val);
17             head = head->next;
18         }
19         for(int i = 0, j = v.size() - 1; i < j; i++, j--){
20             if(v[i] != v[j]) return false;
21         }
22         return true;
23     }
24 };