Write a C++ program + explanation AND comments.

C++, and Comments Please.

Thank you.

Problem 4 (25 points) You have two numbers represented by a linked list, where each node contains a single digit. The digits are stored in reverse order, such that the 1 's digit is at the head of the list. Write a function that adds the two numbers and returns the sum as a linked list Example: Input: (7- > 1- >6)+(5- > 9- >2). That is, 617+295. Output: 2- >1->9. That is, 912