链表节点

template<typename T>
class Node {
public:
    T e;
    Node<T> *next;

    Node(T e, Node<T> *next) : e(e), next(next) {} //这里冒号后面的意思是说, this.e = e;this.next = next;

    Node(T e) : e(e), next(nullptr) {}

    Node() : e(), next(nullptr) {}
};