Add two linked lists

Easy

Let's say you're given two linked lists that each represent a number.

For example, the linked list (1) -> (3) -> (4) -> (7) represents the number 1,347.

Write a function that adds the two input numbers represented by linked lists, and returns the sum represented by a linked list.

Note that the first node is the most significant digit, and the last node is the least significant digit.

For example, a function that's passed these inputs:

(1) -> (4) -> (7)
       (2) -> (3)

should return:

(1) -> (7) -> (0)

Try it first

class Node:
    def __init__(self, data):
        self.data = data
        self.next = None

def add_lists(head_1: Node, head_2: Node) -> Node:
    # implement add_lists
    return None

1class Node:
2    def __init__(self, data):
3        self.data = data
4        self.next = None
5
6def add_lists(head_1: Node, head_2: Node) -> Node:
7    # implement add_lists
8    return None
9

Solution

8 Essential Linked Lists Coding Interview Problems

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