Day-104.cpp

/**
 * 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:
    bool isPalindrome(ListNode* head) {
        stack<int>s; 
        ListNode* temp = head;
        while(temp!=NULL){
            s.push(temp->val);
            temp=temp->next;
        }
        temp = head;
        while(temp!=NULL){
            if(s.top() != temp->val){
                return false;
            }
            s.pop();
            temp = temp->next;
        }
        return true;
    }
};