題目：
Given a singly linked list, determine if it is a palindrome.
Follow up:
Could you do it in O(n) time and O(1) space?
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****************************我是分割線*************************
/**
* Definition for singly-linked list.
* struct ListNode {
* int val;
* ListNode *next;
* ListNode(int x) : val(x), next(NULL) {}
* };
*/
class Solution {
public:
bool isPalindrome(ListNode* head) {
if(head==NULL || head->next==NULL)
return true;
if(head->next->next==NULL)
{
if(head->val==head->next->val)
return true;
else return false;
}
else
{
ListNode* temp=new ListNode(0);
temp->next=head;
ListNode* temp1111=head;
vector coun;
//int i=0;
while(temp->next)
{
coun.push_back(temp1111->val);
//i++;
temp1111=temp1111->next;
temp=temp->next;
}
int sum=coun.size();
int j=0;
for(;j<(sum+1)/2;j++)
{
if(coun[j]==coun[sum-1-j])
continue;
return false;
}
//if(j+1>=(sum+1)/2)
return true;
//else return false;
}
}
};