Learn
Technical Interview Problems in Python: Linked Lists
Add Two Numbers

For our last problem, we’re going to pretend that each node in a linked list holds the digit of a number. The tail node holds the most significant digit and the head node holds the least significant digit.

# 2 -> 4 -> 1 # represents the number 142 # 7 -> 1 # represents the number 17

Given two of these linked lists, write a function that returns the sum of the two numbers as a new linked list.

# 2 -> 4 -> 1 # plus # 7 -> 1 # returns # 9 -> 5 -> 1

To recap:

  • write a function: add_two().
  • add_two() takes two arguments, each an instance of LinkedList.
  • return an instance of LinkedList which contains the sum of the input linked lists.

Instructions

1.

Solve this problem and pass the tests. If you need help, check out the hint!

Folder Icon

Sign up to start coding

Already have an account?