@Override
        public String toString() {
            return "ListNode{" +
                    "val=" + val +
                    ", next=" + next +
                    '}';
        }
You are given two linked lists representing two non-negative numbers.
The digits are stored in reverse order and each of their nodes contain a single digit.
Add the two numbers and return it as a linked list.
<p>
Input: (2 -> 4 -> 3) + (5 -> 6 -> 4)
Output: 7 -> 0 -> 8
java8/src/main/java/com/shekhargulati/leetcode/algorithms/Problem02.java