Assume that a singly linked list is implemented with a header node, but no tail node, and that it maintains only a pointer to the header node. Write a class that includes methods to: 1. return the size of the linked list 2. print the linked list 3. test if a value x is contained in the linked list 4. add a value x if it is not already contained in the linked list 5. Remove a value x if it is contained in the linked list. Singly link list operations. (Sorting) Repeat Problem [2], but first sort list in ascending order. Link list and maths. (Code in C++ both for singly and doubly link list) Given two link lists, L1 and L2, write a C++ code to compute union (L1 U L2) using only the basic link list operations