class Queue:
def __init__(self):
self.storage = LinkedList()
def __str__(self):
return f"{self.storage}"
def __len__(self):
return len(self.storage)
def enqueue(self, value):
self.storage.add_to_tail(value)
def dequeue(self):
if len(self.storage) > 0:
return self.storage.remove_from_head()
class Queue:
def __init__(self):
self.size = 0
self.storage = LinkedList()
def __len__(self):
if self.size >= 0:
return self.size
else:
return 0
def enqueue(self, value):
self.storage.add_to(value)
self.size += 1
def dequeue(self):
if self.size > 0:
value = self.storage.remove_from_head()
self.size -= 1
return value
class Queue:
def __init__(self):
self.size = 0
self.storage = LinkedList()
def __len__(self):
return self.size
def enqueue(self, value):
# self.storage.append(value)
self.storage.add_to_end(value)
self.size += 1
def dequeue(self):
# if len(self.storage) != 0:
# return self.storage.pop(0)
if not self.storage.head:
return None
else:
self.size -= 1
return self.storage.remove_from_head()
class Queue:
def __init__(self):
self.size = 0
self.storage = LinkedList()
def __len__(self):
return self.size
def enqueue(self, value):
self.size += 1
self.storage.add_to_end(value)
def dequeue(self):
if self.size > 0:
self.size -= 1
return self.storage.remove_from_head()
# 3.
# The difference between linked lists and array methods are that the array methods are already built in parts of the storage list.
# We can use these instead of writing out our own in a linked list class, and we can reference indeces of the array whereas in linked
# lists we cannot.
class Stack:
def __init__(self):
self.size = 0
self.storage = LinkedList()
def __len__(self):
return self.size
def push(self, value):
self.size += 1
self.storage.add_to_head(value)
def pop(self):
if self.size > 0:
self.size -= 1
return self.storage.remove_from_head()
# 3.
# The difference between linked lists and array methods are that the array methods are already built in parts of the storage list.
# We can use these instead of writing out our own in a linked list class, and we can reference indeces of the array whereas in linked
# lists we cannot. Additionally when implementing linked lists with stacks, it seems we need to have an additional 'Remove from tail'
# method in order to properly pop() in the way that is expected with a stack.
class Stack:
def __init__(self):
self.size = 0
self.storage = LinkedList()
# get stack length/size
def __len__(self):
return self.size
def push(self, value):
# add one to size
self.size += 1
# add item to top of stack
self.storage.add_to_head(value)
def pop(self):
# if stack empty, can't remove anything
if self.size == 0:
return None
else:
# subtract one from size
self.size -= 1
# remove from top of stack & return item
return self.storage.remove_from_head()
class Queue:
def __init__(self):
self.size = 0
self.storage = LinkedList()
# return queue size/length
def __len__(self):
return self.size
def enqueue(self, value):
# add one to queue size/length
self.size += 1
# add item to end of queue
self.storage.add_to_end(value)
def dequeue(self):
# if queue empty, can't remove
if self.size == 0:
return None
else:
# remove one from queue size/length
self.size -= 1
# remove one item from top of queue
return self.storage.remove_from_head()
