def reverse(linked_list):
"""
Reverse the inputted linked list
Args:
linked_list(obj): Linked List to be reversed
Returns:
obj: Reveresed Linked List
"""
new_list = LinkedList()
node = deepcopy(linked_list.head)
# A bit of a complex operation here. We want to take the
# node from the original linked list and prepend it to
# the new linked list
while node:
old_head = new_list.head
new_node = node
node = node.next
new_node.next = old_head
new_list.head = new_node
return new_list
def create_linked_list_with_list_of_nodes(nodes):
linked_list = LinkedList(nodes[0]) # head
for node in nodes[1:]:
linked_list.insert(node)
return linked_list
def create_linked_list_with_list_of_values(values):
linked_list = LinkedList(Node(values[0])) # head
for value in values[1:]:
linked_list.insert(Node(value))
return linked_list
def setUp(self):
head = Node(1)
self.linked_list = LinkedList(head)
class TestLinkedList(unittest.TestCase):
def setUp(self):
head = Node(1)
self.linked_list = LinkedList(head)
def test_insert(self):
new_node = Node(2)
self.linked_list.insert(new_node)
expected = 2
result = self.linked_list.get_last_node().value
assert_that(expected).is_equal_to(result)
def test_find(self):
self.linked_list.insert(Node(3))
self.linked_list.insert(Node(4))
result = self.linked_list.find(3)
expected = Node(3)
assert_that(expected.value).is_equal_to(result.value)
def test_remove(self):
self.linked_list.insert(Node(5))
self.linked_list.insert(Node(6))
result = self.linked_list.remove(5)
assert_that(result).is_true()
def test_remove_non_existing(self):
self.linked_list.insert(Node(5))
self.linked_list.insert(Node(6))
with self.assertRaises(ValueError):
self.linked_list.remove(100)
def test_iteration(self):
self.linked_list.insert(Node(2))
self.linked_list.insert(Node(3))
self.linked_list.insert(Node(4))
numbers = [1, 2, 3, 4]
for val, num in zip(self.linked_list, numbers):
assert_that(val).is_equal_to(num)
def test_length(self):
self.linked_list.insert(Node(2))
self.linked_list.insert(Node(3))
self.linked_list.insert(Node(4))
self.linked_list.insert(Node(5))
self.linked_list.insert(Node(6))
assert_that(6).is_equal_to(len(self.linked_list))
def test_get_nth_node(self):
nth = 3
self.linked_list.insert(Node(2))
self.linked_list.insert(Node(3))
self.linked_list.insert(Node(4))
assert_that(nth).is_equal_to(self.linked_list.get_nth_node(nth).value)
Reverse the inputted linked list
Args:
linked_list(obj): Linked List to be reversed
Returns:
obj: Reveresed Linked List
"""
new_list = LinkedList()
node = deepcopy(linked_list.head)
# A bit of a complex operation here. We want to take the
# node from the original linked list and prepend it to
# the new linked list
while node:
old_head = new_list.head
new_node = node
node = node.next
new_node.next = old_head
new_list.head = new_node
return new_list
list1 = LinkedList()
for value in [4, 2, 5, 1, -3, 0]:
list1.append(value)
print("Pass" if (list(list1) == list(reverse(reverse(list1)))) else "Fail")
# if a node refers to itself, that's a little loop
if slow.next == slow:
return True
# slow pointer moves one node
slow = slow.next
# fast pointer moves two nodes
fast = fast.next.next
if slow == fast:
return True
# If we get to a node where fast doesn't have a next node or doesn't exist itself,
# the list has an end and isn't circular
return False
list_with_loop = LinkedList([2, -1, 3, 0, 5])
# Creating a loop where the last node points back to the second node
loop_start = list_with_loop.head.next
node = list_with_loop.head
while node.next:
node = node.next
node.next = loop_start
print("Pass" if (is_circular(list_with_loop) is True) else "Fail")
print("Pass" if (is_circular(LinkedList([-4, 7, 2, 5, -1])) is False) else "Fail")
print("Pass" if (is_circular(LinkedList([1])) is False) else "Fail")
def __init__(self, max_len=10):
self._array = [LinkedList() for _ in range(max_len)]
self._max_len = max_len