下面函数用“哑结点”统一处理删除单向链表中的头结点与中间结点。横线处应填 ()。

cpp
复制
1struct Node {
2    int val;
3    Node *next;
4    Node(int v): val(v), next(nullptr){}
5};
6Node* eraseAll(Node* head, int x){
7    Node dummy(0);
8    dummy.next = head;
9    Node* cur = &dummy;
10    while(cur->next){
11        if(cur->next->val == x){
12            Node* del = cur->next;
13            ______________________
14            delete del;
15        }else cur = cur->next;
16    }
17    return dummy.next;
18}