下列C++代码用循环链表解决约瑟夫问题，即假设n个人围成一圈，从第一个人开始数，每次数到第k 个
的人就出圈，输出最后留下的那个人的编号。横线上应填写（ ）。
struct Node { int data; Node* next;}; Node* createCircularList(int n) { Node* head = new Node{1, nullptr}; Node* prev = head; for (int i = 2; i <= n; ++i) { Node* node = new Node{i, nullptr}; prev->next = node; prev = node; } prev->next = head; return head;} int fingLastSurvival(int n, int k) { Node* head = createCircularList(n); Node* p = head; Node* prev = nullptr; while (p->next != p) { for (int count = 1; count < k; ++count) { prev = p; p = p->next; } _______________________ } cout << "最后留下的人编号是: " << p->data << endl; delete p; return 0;}