I need c or c++ code for this problem with the describtion of the data structures and algorithm that used to solve the problem

4. Deduplication on a Linked List (basic) Given a singly linked list L with integer keys, you are supposed to remove the nodes with duplicated absolute values of the keys. That is, for each value K. only the first node of which the value or absolute value of its key equals K will be kept. At the mean time, all the removed nodes must be kept in a separate list. For example, given I being 21--15--15---7--15, you must output 21--15---7, and the removed list -15-15. Input Specification: Each input file contains one test case. For each case, the first line contains the address of the first node, and a positive N