Add Two Numbers — medium DSA Problem

You are given two non-empty linked lists representing two non-negative integers. The digits are stored in reverse order, and each of their nodes contains a single digit. Add the two numbers and return the sum as a linked list.

You may assume the two numbers do not have leading zeros, except the number 0 itself.

Example 1:

Input:
2 4 3
5 6 4
Output: 7 0 8

(342 + 465 = 807)

Example 2:

Input:
0
0
Output: 0

Example 3:

Input:
9 9 9 9 9 9 9
9 9 9 9
Output: 8 9 9 9 0 0 0 1

Constraints:

The number of nodes in each list is in the range [1, 100]
0 ≤ Node.val ≤ 9

Input format: Two lines of space-separated digits (each list in reverse order).

Output format: Space-separated digits of the result list (in reverse order).