如何在 C++ 中实现元素可以是整数或链表本身的链表？

Question

Assume I have a linked list, in which its elements can be integers or linked lists themselves. I also have a method named add_last . How can I implement such a linked list?

For example:

LL *l = new LL();
l->add_last(1); 
l->add_last(2);

LL *l1 = new LL();
l1->add_last(3);
l1->add_last(4);

l1->add_last(l);

The expected output for l1 should be [[3, 4], 1, 2] .

[3, 4] is considered as an element, 1 is an element, and 2 is an element.

In the end, the list has 3 elements, in which 1st node is a list, 2nd node is an integer, and 3rd node is also an integer.

Answer 1

Consider using structs with the various data types as members, and overloaded parameterized constructors. It would be inefficient but I believe there isn't a way to do this on C++.

You can use template classes so that your code works with any class but the linked list itself would still have only one class.

Answer 2

You could define a base node class with a next pointer and a node type, and define an inherited class that is the base class plus an integer, and define an inherited class that is the base class plus a pointer to a base class node. add_last() would select which inherited class node to use based on input and set the base node type based on what type of node it is (integer or pointer to node). An output list function would select which inherited class node to use based on the node type.