def add_lists(a: SinglyNode, b: SinglyNode, carry=0) -> SinglyNode:
result = carry
if a is None and b is None:
if result != 0:
return SinglyNode(carry)
return None
elif a is not None and b is not None:
result += a.data + b.data
elif a is not None:
result += a.data
else:
result += b.data
if result >= 10:
carry = 1
result = result % 10
else:
carry = 0
c = SinglyNode(result)
c.next = add_lists(a.next, b.next, carry)
return c
def delete_middle(node: SinglyNode):
while node.next is not None:
node.data = node.next.data
if node.next.next is None:
node.next = None
break
node = node.next
def push(self, data: Any):
if self.top is None:
self.top = SinglyNode(data)
self.min_stack.append(data)
else:
if data <= self.min_stack[-1]:
self.min_stack.append(data)
new_node = SinglyNode(data)
new_node.next = self.top
self.top = new_node
def partition3(node: SinglyNode, x: Any) -> SinglyNode:
head = node
tail = node
while node is not None:
next_node = node.next
if node.data < x:
node.next = head
head = node
else:
tail.next = node
tail = node
node = next_node
tail.next = None
return head_to_linked_list(head)
slow = head
fast = head.next
while True:
if slow == fast:
return True
elif fast is None or fast.next is None:
return False
slow = slow.next
fast = fast.next.next
# Circular list
x = SinglyNode(2)
x.next = SinglyNode(1)
x.next.next = SinglyNode(3)
x.next.next.next = x
Solution(
is_circlular,
[
Test(
[x],
True,
None
),
Test(
[parse('1>2>3>1>2>4').head],
False,
None