// 快慢指针找中间节点，将后面链表逆置，再进行比较 ListNode *slow = A, *fast = A; while (fast && fast->next) { slow = slow->next; fast = fast->next->next; } ListNode *B = nullptr; while (slow) { ListNode *tmp = slow->next; slow->next = B; B = slow; slow = tmp; } while (B) { if (A->val != B->val) return false; A = A->next; B = B->next; } return true;