2.5 - Sum Lists

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. FOLLOW UP Suppose the digits are stored in forward order. Repeat the above problem. EXAMPLE Input: (6 -> 1 -> 7) + (2 -> 9 -> 5).That is, 617 + 295. Output: 9 -> 1 -> 2. That is, 912.