class Queue:
def __init__(self):
self.__list = LinkedList()
self.__rear = Node()
self.__front = Node()
self.__size = 0
def size(self):
return self.__list.size()
def is_empty(self):
return self.size == 0
def front(self):
return self.__front
def enqueue(self, elem):
e = Node(elem)
if self.__list.head() != None:
self.__rear.set_next(e)
else:
self.__list.add_head(e)
self.__front = e
self.__rear = e
def dequeue(self):
if self.__list.head() != None:
temp = self.__front
self.__list.remove_head()
self.__front = self.__front.get_next()
return temp.get_element()
else:
print('Queue is empty, cannot remove element!')
return 1
def __repr__(self):
result = "-> "
p = self.__list.head()
print(p)
if p is not None:
while p is not None:
result += "%s " % str(p.get_element())
p = p.get_next()
return result
class stackADT_linkedlist:
def __init__(self):
self.storage = LinkedList()
#counter will be used to get full size of the list
self.counter = 0
def stackPUSH(self, item):
'''adds element to stack - initially named push, renamed to prevent confusion when reading world.py'''
self.storage.add_head(Node(item))
#increases total counter by 1
self.counter += 1
def pop(self):
'''removes element from stack'''
#reduces total counter by 1
self.counter -= 1
return self.storage.remove_head()
def viewStack(self):
'''easy way to view entire contents of stack'''
return self.storage
def size(self):
return self.counter
