def reorder(head):
n = size(head)
head2 = advance(head, n / 2)
head2 = reverse(head2)
curr = head
while curr:
nxt = curr.next
curr.next = head2
curr, head2 = head2, nxt
def is_palindrome(head):
n = size(head)
head2 = advance(head, n / 2)
head2 = reverse(head2)
return is_same(head, head2)
def test_trivial_true():
head1 = LinkedListNode(0)
head2 = LinkedListNode(0)
assert is_same(reverse(head1), head2)
def test_trivial():
assert reverse(None) is None
def test_nontrivial_false():
head1 = LinkedListNode(0, LinkedListNode(1, LinkedListNode(2)))
head2 = LinkedListNode(1, LinkedListNode(2))
assert not is_same(reverse(head1), head2)
def test_trivial_false():
head1 = LinkedListNode(0)
head2 = LinkedListNode(1)
assert not is_same(reverse(head1), head2)