class Stack:
def __init__(self):
self.size = 0
#self.storage = [] ##array code commented out
self.storage = LinkedList()
def __len__(self):
#return len(self.storage)
return self.size
def push(self, value):
#return self.storage.append(value)
self.storage.add_to_end(
value) ##from ll functions add to end of stack. LIFO
self.size += 1 #size of in +1
def pop(self):
#if len(self.storage) == 0:
#return None
#else:
#return self.storage.pop()
if not self.storage.head:
return None
else:
self.size -= 1 #remove 1 from in
return self.storage.remove_at_end(
) #rmeove last input from end of stack. LIFO
class Queue:
def __init__(self):
self.size = 0
#self.storage = [] ##array code commented out
self.storage = LinkedList()
def __len__(self):
#return len(self.storage)
return self.size
def enqueue(self, value):
#self.storage.append(value)
self.storage.add_to_end(value) #adds to back of que
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() #takes from front of que
