Hi, here’s your problem today. This problem was recently asked by AirBNB:

Given a linked list and a number k, rotate the linked list by k places.

Here’s some starter code and an example:

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

  def __str__(self):
    current = self
    ret = ''
    while current:
      ret += str(current.value)
      current = current.next
    return ret

def rotate_list(list, k):
  # Fill this in.

# Order is 1, 2, 3, 4
llist = Node(1, Node(2, Node(3, Node(4))))

# Order should now be 3, 4, 1, 2
print(rotate_list(llist, 2))
# 3412