Add two numbers stored as linked lists
Coding problemMediumAsked in: Adobe, Amazon, Apple, Google, Meta, Microsoft
Two non-negative whole numbers are stored in linked lists, one digit per node, with the lowest digit first. For example, the list 2, 4, 3 stands for the number 342. Return their sum as a linked list in the same form.
Neither number has leading zeros, except the number 0 itself, which is a single node holding 0. The numbers can have up to 100,000 digits, far more than any built-in integer type holds.
Examples
Example 1
Input: first = [2,4,3], second = [5,6,4]
Output: [7,0,8]
342 + 465 = 807.
Example 2
Input: first = [0], second = [0]
Output: [0]
Example 3
Input: first = [9,9,9,9], second = [1]
Output: [0,0,0,0,1]
9999 + 1 = 10000.
Constraints
- Each list has between 1 and 100,000 nodes
- Each node holds a digit from 0 to 9
- The last node is not 0 unless the list is the single node 0
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