https://leetcode.com/problems/palindrome-linked-list/

class Solution
{
private:
	ListNode* get_node(ListNode* head, int n)
	{
		for (int i = 1; i < n; ++i)
		{
			head = head->next;
		}
		return head;
	}
public:
	bool isPalindrome(ListNode* head)
	{
		int sz = 0, m;
		ListNode* t = head;
		while (t != NULL)
		{
			sz++;
			t = t->next;
		}
		m = sz / 2;
		t = get_node(head, sz - m + 1);
		for (int i = 0; i < m; ++i)
		{
			if (t->val != get_node(head, m - i)->val)
				return 0;
			else
				t = t->next;
		}
		return 1;

	}
};