//cpp:
/**
 * Definition for singly-linked list.
 * struct ListNode {
 *     int val;
 *     ListNode *next;
 *     ListNode(int x) : val(x), next(NULL) {}
 * };
 */
class Solution {
public:
    ListNode* Reverse(ListNode* head){
        ListNode *p1=NULL;
        
        while(head){
            ListNode *p=new ListNode(head->val);
            p->next=p1;
            p1=p;
            head=head->next;
        }
        return p1;
    }
    bool isPalindrome(ListNode* head) {
        ListNode* root=head;
        ListNode* root1=Reverse(head);
        while(root1&&root&&root1->val==root->val){
            root1=root1->next;
            root=root->next;
        }
        if(!root1&&!root){
            return true;
        }else{
            return false;
        }
    }
    
};