Add Two Numbers

Add Two Numbers

LeetCode Problem

• Problem Number: 2
• Problem Link: https://leetcode.com/problems/add-two-numbers/
• Difficulty: Medium
• Topics: Linked List, Math, Recursion

Problem Description

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

You may assume:

• The two numbers do not contain any leading zero, except the number 0 itself
• Each linked list represents a valid number

Examples

Example 1:

Input: l1 = [2,4,3], l2 = [5,6,4]
Output: [7,0,8]
Explanation: 342 + 465 = 807

Example 2:

Input: l1 = [0], l2 = [0]
Output: [0]

Example 3:

Input: l1 = [9,9,9,9,9,9,9], l2 = [9,9,9,9]
Output: [8,9,9,9,0,0,0,1]

Constraints

• The number of nodes in each linked list is in the range [1, 100]
• 0 <= Node.val <= 9
• It is guaranteed that the list represents a number that does not have leading zeros