Add Two Numbers — Medium Coding Interview Question

You are given two non-empty linked lists representing two non-negative integers, with digits stored in reverse order. Add the two numbers and return the sum as a linked list, also in reverse order.

Example

Input: l1 = [2,4,3], l2 = [5,6,4]

Output: [7,0,8]

Explanation: 342 + 465 = 807.

Constraints

• The number of nodes in each list is in [1, 100]
• 0 ≤ Node.val ≤ 9
• No leading zeros, unless the number itself is 0

Topics & Companies

Topics: linked-list, recursion

Asked by: Amazon, Microsoft, Meta, Adobe

Optimal Solution Complexity

Time complexity: O(max(m, n)). Space complexity: O(max(m, n)).

Practice more

• All DSA Problems
• DSA Patterns