class TestLinkedList:
new_list = LinkedList()
def testNewLinkedList(self):
self.new_list = LinkedList()
assert self.new_list.head == None
def testAddNode(self):
self.new_list.addNode('node_1')
assert self.new_list.head.data == 'node_1'
def testGetLength(self):
size = self.new_list.length()
assert size == 1
self.new_list.addNode('node_2')
size = self.new_list.length()
assert size == 2
self.new_list.addNode('node_3')
self.new_list.addNode('node_4')
def testStr(self):
print(self.new_list)
def testDelOldestNode(self):
node = self.new_list.delOldestNode()
assert self.new_list.length() == 3
assert node == 'node_1'
def testDelNewestNode(self):
node = self.new_list.delNewestNode()
assert self.new_list.length() == 2
assert node == 'node_4'
def clone(ll: LinkedList) -> LinkedList:
clone_head = ll.head
pos1 = ll.head
pos2 = ll.head.next
# duplicating all elements (by value in the linked list)
# [a -> b -> c becomes a -> a -> b -> b -> c -> c]
for _ in range(ll.length):
pos1.next = Node(pos1.val)
pos1 = pos1.next
pos1.next = pos2
pos1 = pos1.next
if pos2 is None:
break
pos2 = pos2.next
# setting the clone head to the proper position
clone_head = clone_head.next
pos1 = ll.head
# setting the random pointer of the cloned linked list
# (every 2nd element in the new linked list: a -> [a] -> b -> [b] -> c -> [c])
for _ in range(ll.length - 1):
pos1.next.random_ptr = pos1.random_ptr
pos1 = pos1.next.next
# reverting the linked list to its original form
pos1 = ll.head
pos2 = ll.head.next
for _ in range(ll.length - 1):
pos1.next = pos2.next
pos2.next = pos2.next.next
pos1 = pos1.next
if pos2.next == None:
break
pos2 = pos2.next
# creating the cloned linked list from the generated nodes
cloned_LL = LinkedList()
cloned_LL.head = clone_head
cloned_LL.length = ll.length
cloned_LL.rear = pos2
return cloned_LL
ll1 = LinkedList()
ll1.add(5)
ll1.add(6)
ll1.add(7)
ll1.add(8)
ll2 = LinkedList()
ll2.add(1)
ll2.add(2)
ll2.add(3)
ll2.add(4)
ll3 = LinkedList()
ll3.add(9)
ll3.rear.next = ll1.head.next.next
ll3.rear = ll3.rear.next.next
ll3.length = 3
print("Linked List 1:", ll1)
print("Linked List 2:", ll2)
print("Linked List 3:", ll3)
print(common_node_pos(ll1, ll2))
print(common_node_pos(ll1, ll3).val)
"""
SPECS:
TIME COMPLEXITY: O(n)
SPACE COMPLEXITY: O(1)
"""