这时双向链表的C++实现，里面定义了一个链表类。含有丰富的成员函数。比如：拷贝构造函数，析构函数，插入函数，删除函数，排序函数等等。总之，里面的函数肯定够你用的。-At this time, two-way linked list C++ achieved, which defines a linked list class. Rich in member function. Example: copy constructor, destructor, insert function, delete function, sort function. In short, the function inside certainly sufficient for you.