class Stack:
def __init__(self):
self.stack = LinkedList()
def push(self, obj):
self.stack.add(obj)
def pop(self):
return self.stack.poll_last()
def peak(self):
return self.stack.get_last()
def size(self):
return self.stack.size()
def isEmpty(self):
return self.stack.is_empty()
class DeQueue:
def __init__(self):
self.queue = LinkedList()
def enqueue_from_rear(self, obj):
self.queue.add(obj)
def enqueue_from_front(self, obj):
self.queue.add_first(obj)
def dequeue_from_rear(self):
return self.queue.poll_last()
def dequeue_from_front(self):
return self.queue.poll_first()
def size(self):
return self.queue.size()
def is_empty(self):
return self.queue.is_empty()