def test_add_at_tail(self):
dll = Dll()
dll.add_at_head("apple")
dll.add_at_head("orange")
dll.add_at_tail("mango")
assert str(dll.head) == "orange"
assert dll.size_dll() == 3
def printReverse(current):
"""Print all the elements of the list in reverse."""
temp = current
if current is None:
return
# Traverse to the end
while current.next:
current = current.next
# Traverse backward
while current:
print(current.data)
current = current.prev
if __name__ == "__main__":
dll = Dll()
dll.add_at_head(1)
dll.add_at_head(3)
dll.add_at_tail(5)
dll.add_at_tail(7)
print("Head of linked list:")
print(dll.head)
print("Forward:")
printForward(dll.head)
print("Reverse:")
printReverse(dll.head)
current.prev = None
current = None
return
# case 4:
else:
prev_node = current.prev
prev_node.next = None
current.prev = None
current = None
return
current = current.next
if __name__ == "__main__":
dll = Dll()
dll.add_at_tail(1)
dll.add_at_tail(2)
dll.add_at_tail(3)
dll.add_at_tail(2)
dll.add_at_tail(1)
dll.add_at_tail(4)
dll.add_at_tail(2)
dll.add_at_tail(1)
print("List: ")
dll.print_dll()
print("\n")
print("List after removing duplicates: ")
remove_duplicates(dll.head)
dll.print_dll()