implement a class called Distinct_list (in short, D_list) that maintains a group of integers. The class is expected to have the following functionalities takes user inputs and initialize its elements accordingly,

2) remove the duplicate elements, if there is any, and

3) sorts the duplicated-free list through a merge-sort procedure, where the stl class list is expected to be used.-implement a class called Distinct_list (in short, D_list) that maintains a group of integers. The class is expected to have the following functionalities takes user inputs and initialize its elements accordingly,

2)　　 remove the duplicate elements, if there is any, and

3)　　 sorts the duplicated-free list through a merge-sort procedure, where the stl class list is expected to be used.