def insert(
self, index, data
): #runs in O(n) time. #we are inserting the data at the index you assign to.
newNode = ListNode(data, None, None)
itrNode = self.__start
counter = 1
while (
counter < index
): # we are going to loop based on where we want to insert the new node
itrNode = self.__start.getNext()
# this iteraters through each node
counter = counter + 1 # we are keeping track of whwere the index is in the linked list.
if (index == 0):
self.push_front(data)
elif (index > self.__length):
self.push_back(data)
else:
#A in the code will be itrNode
#B in the code will be itrNode.getPrevious();
A = itrNode
B = itrNode.getPrevious()
newNode.setPrevious(B)
newNode.setNext(A)
B.setNext(newNode)
A.setPrevious(newNode)
class MyList:
__start = None
__end = None
__length = None
def __init__(self):
self.__length = 0
def push_back(self, data): #runs in constant time. # this is append
if (self.__start is
None): # checks to see if there is no node out there aka none
self.__start = ListNode(data, None, None)
# we just created a new node and assigned start to that node.
self.__end = self.__start
# set the start and end to the existing Node as shown line above(is this correct?)
else:
newNode = ListNode(data, None, self.__end)
# if there is already a node out there, we assign a new node called newnode. the end points to that
self.__end.setNext(newNode)
# using pattern below but unclear
self.__end = newNode #see line 26
print("Implement Push_back")
def push_front(self, data): #runs in constant time
if (self.__start is
None): # checks to see if there is no node out there aka none
self.__start = ListNode(data, None, None)
# we just created a node and assigned the start to it.
self.__end = self.__start
# see line 12.
else:
newNode = ListNode(data, None, self.__start)
# if there is already a node out there we create a new node and we assign it start to it because we push to the front.
self.__start.setPrevious(newNode)
# because this node will be in front, and start is the exisiting node, we set the new start to the previous node we just created above.
self.__start = newNode
#assign self.__start to newnode. !!!Confused- why do i need line 25 then...
print("Implement push_Front")
#if you had insert(3, data) i want to start with the data to become the third node of the list. so what is the third node of the list and then assign data into third node.
def insert(
self, index, data
): #runs in O(n) time. #we are inserting the data at the index you assign to.
newNode = ListNode(data, None, None)
itrNode = self.__start
counter = 1
while (
counter < index
): # we are going to loop based on where we want to insert the new node
itrNode = self.__start.getNext()
# this iteraters through each node
counter = counter + 1 # we are keeping track of whwere the index is in the linked list.
if (index == 0):
self.push_front(data)
elif (index > self.__length):
self.push_back(data)
else:
#A in the code will be itrNode
#B in the code will be itrNode.getPrevious();
A = itrNode
B = itrNode.getPrevious()
newNode.setPrevious(B)
newNode.setNext(A)
B.setNext(newNode)
A.setPrevious(newNode)
def get(
self, index
): #runs in O(n) time. # we are getting the specific node? EG : we are trying to get index node, or lets say 3
if (self.__start is
None): # checks to see if there is even a start to begin with
return None
else:
i = 0
# set to 0
tempNode = self.__start
while (i < index):
tempNode = tempNode.getNext()
i = i + 1
return tempNode
print("Implement")
def length(self): #runs in constant time.
counter = 0
tempNode = self.__start
while (tempNode.getNext() != None):
tempNode = tempNode.getNext()
counter = counter + 1
self.__length = counter
return counter
def print(
self
): #runs in O(n) time. Prints all the data in the list with a space in
if (self.__start is None):
return None
else:
tempNode = self.__start
templist = []
while (tempNode.getNext() != None):
templist = tempNode
tempNode = tempNode.getNext
print(*templist)
