def reverse(head):
new_head = None
p = head
while p is not None:
node = Node(p.data)
node.next = new_head
new_head = node
p = p.next
return new_head
def insert(self, item: Any) -> None:
self._size += 1
new_node = Node(item)
if self.last is None:
self.head = new_node
else:
self.last.next = new_node
self.last = new_node
def partition_linkedlist(L, x):
"""
Time = O(n), Space = O(n)
"""
node_x = Node(x)
head = tail = node_x
curr = L.head
while curr is not None:
temp = Node(curr.data)
if curr.data < x:
temp.next = head
head = temp
else:
tail.next = temp
tail = temp
curr = curr.next
L.head = head
L.remove(x)
def add(N1, N2, carry):
# we are done if both lists are null and the carry value is 0
if N1 is None and N2 is None and carry == 0:
return None
result = Node(0)
# add value and the data from L1 and L2
value = carry
if N1 is not None:
value += N1.data
if N2 is not None:
value += N2.data
result.data = value % 10
# recurse
if N1 is not None or N2 is not None:
more = add(N1.next if N1 is not None else None,
N2.next if N2 is not None else None,
1 if value >= 10 else 0)
result.next = more
return result
def test_is_palindrome():
a = Node(1, Node(2, Node(3, Node(2, Node(1, None)))))
print_linkedlist(a)
print(is_palindrome(a))
a = Node(1, Node(2, Node(2, Node(1, None))))
print_linkedlist(a)
print(is_palindrome(a))
a = Node(1, Node(2, Node(3, Node(3, Node(1, None)))))
print_linkedlist(a)
print(is_palindrome(a))
def test_reverse():
a = Node(1, Node(2, Node(3, Node(4, None))))
b = reverse(a)
print_linkedlist(b)
def insert_before(N, data):
node = Node(data)
node.next = N
return node