def _sum_normal(first_node, second_node):
head, carry = carry_and_sum(first_node, second_node)
if carry == 0:
return head
new_head = SingleLinkNode(carry)
new_head.next = head
return new_head
def linked_number_reverse(num):
if num < 0:
return None
if num < 10:
return SingleLinkNode(num)
head = SingleLinkNode(num % 10)
head.next = linked_number_reverse(num / 10)
return head
def _sum_reverse(first_node, second_node, carry):
if first_node is None and second_node is None:
if carry == 1:
return SingleLinkNode(carry)
else:
return None
addition = carry
if first_node is not None:
addition += first_node.val
if second_node is not None:
addition += second_node.val
current = SingleLinkNode(addition % 10)
current.next = _sum_reverse(first_node.next, second_node.next, addition / 10)
return current
def complete_with_zeros(number_node, zeros):
if zeros <= 0:
return number_node
head = SingleLinkNode(0)
head.append(complete_with_zeros(number_node, zeros - 1))
return head