def test_to_list():
cdll = CircularDoublyLinkedList()
node_1 = Node(RandomString.make())
cdll.insert_at_beg(node_1)
node_2 = Node(RandomString.make())
cdll.insert_after(node_1, node_2)
node_3 = Node(RandomString.make())
cdll.insert_after(node_2, node_3)
assert cdll.to_list() == [node_1.data, node_2.data, node_3.data]
def test_remove_from_end():
cdll = CircularDoublyLinkedList()
node_1 = Node(RandomString.make())
node_2 = Node(RandomString.make())
node_3 = Node(RandomString.make())
cdll.insert_at_beg(node_3)
cdll.insert_at_beg(node_2)
cdll.insert_at_beg(node_1)
assert cdll.to_list() == [node_1.data, node_2.data, node_3.data]
cdll.remove(node_3)
assert cdll.to_list() == [node_1.data, node_2.data]
def test_all_inserts():
cdll = CircularDoublyLinkedList()
node_1 = Node(RandomString.make())
node_2 = Node(RandomString.make())
node_3 = Node(RandomString.make())
node_4 = Node(RandomString.make())
cdll.insert_at_beg(node_1)
cdll.insert_after(node_1, node_2)
cdll.insert_at_end(node_4)
cdll.insert_before(node_4, node_3)
assert cdll.to_list() == [
node_1.data, node_2.data, node_3.data, node_4.data
]
def test_get_node():
cdll = CircularDoublyLinkedList()
node_1 = Node(RandomString.make())
node_2 = Node(RandomString.make())
node_3 = Node(RandomString.make())
cdll.insert_at_beg(node_1)
assert node_1 == cdll.get_node(0)
assert cdll.get_node(1) is None
cdll.insert_after(node_1, node_2)
cdll.insert_after(node_2, node_3)
assert node_2 == cdll.get_node(1)
assert node_3 == cdll.get_node(2)
assert cdll.get_node(3) is None
assert cdll.get_node(999) is None
class Circle:
def __init__(self):
"""
First, the marble numbered 0 is placed in the circle... This marble is designated the current marble.
"""
self._data = CircularDoublyLinkedList()
node = Node(0)
self._data.insert_at_beg(node)
self.current = node
def move(self, n):
"""
Move n positions around the circle. n can be positive (clockwise) or negative (counter-clockwise).
Return the node at the new position.
"""
node = self.current
while n:
if n > 0:
node = node.next
n -= 1
else:
node = node.prev
n += 1
return node
def place(self, val):
node = Node(val)
to = self.move(1)
self._data.insert_after(to, node)
self.current = node
@property
def current(self):
return self._current
@current.setter
def current(self, value):
self._current = value
def remove(self, node):
self._data.remove(node)
# Make sure current stays valid.
# Did we remove the only node, or the current node?
if self._data.first == None:
self.current = None
elif self.current == node:
self.current = node.next
def __repr__(self):
return f"Circle(data: {repr(self._data)}, current node: {self.current.data})"
def test_one_node():
cdll = CircularDoublyLinkedList()
node = Node(RandomString.make())
cdll.insert_at_beg(node)
assert cdll.to_list() == [node.data]