def test_linking_nodes(self):
node1 = Node('A')
node2 = Node('B')
node3 = Node('C')
# Link nodes together
node1.next = node2
node1.prev = None
node2.next = node3
node2.prev = node1
node3.prev = node2
node3.next = None
# Node links should be transitive
assert node1.prev is None
assert node1.next is node2 # One link
assert node2.prev is node1
assert node1.next.next is node3 # Two links
assert node3.prev is node2
assert node3.next is None
def FlattenNode(pre: Node, cur: Node) -> Node:
if not cur:
return pre
pre.next = cur
cur.prev = pre
tmpnode = cur.next
childnode = FlattenNode(cur, cur.child)
cur.child = None
return FlattenNode(childnode, tmpnode)
def test_node_attributes():
head = Node(1)
assert head.prev is None
assert head.next is None
previous = Node(0)
head.prev = previous
assert head.prev is previous
assert head.next is None
assert head.data == 1
assert head.prev.prev is None
assert head.prev.data == 0
assert repr(previous) == "Node(0)"
next = Node(2)
head.next = next
assert head.prev is previous
assert head.next is next
assert head.data == 1
assert head.next.next == None
assert head.prev.prev == None
assert head.next.data == 2
assert repr(next) == "Node(2)"