请牢记检测回文串的模板

/*** Definition for singly-linked list.* struct ListNode {*     int val;*     struct ListNode *next;* };*/
bool isPalindrome(struct ListNode* head) {int size=0;struct ListNode* point=head;while(point){size++;point=point->next;}int arr[size];int num = 0;while(head){arr[num++]= head->val;head = head->next;} int kuai = num - 1;int man = 0;while(man < kuai){if(arr[man] != arr[kuai]){return false;}man++;kuai--;} return true;     
}