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): self.size -= 1 self.storage.remove_tail()
class Stack: def __init__(self): self.storage = LinkedList() def __len__(self): return self.storage.length def push(self, value): self.storage.add_to_tail(value) def pop(self): if self.storage.length == 0: return None return self.storage.remove_tail()
class Stack: def __init__(self): self.size = 0 self.storage = LinkedList() def __len__(self): return self.size def push(self, value): self.storage.add_to_tail(value) self.size += 1 def pop(self): if self.size == 0: return None self.size -= 1 return self.storage.remove_tail()
class Stack: def __init__(self): self.size = 0 self.storage = LinkedList() def __len__(self): return len(self.storage) def __str__(self): return str(self.storage) def push(self, value): self.storage.add_to_tail(value) def pop(self): if len(self.storage) > 0: return self.storage.remove_tail()
class LinkedListStack: def __init__(self): self.size = 0 self.storage = LinkedList() # len returns the number of elements in the stack. def __len__(self): return self.size # push adds an item to the top of the stack. def push(self, value): self.storage.add_to_tail(value) self.size += 1 # pop removes and returns the element at the top of the stack def pop(self): if self.size == 0: return None self.size -= 1 return self.storage.remove_tail()
class Stack: def __init__(self): self.size = 0 self.storage = LinkedList() self.head = None self.tail = None def __len__(self): return self.size def push(self, value): # size of LL gets increased by 1 every time we push self.size += 1 return self.storage.add_to_tail(value) def pop(self): # check if LL is empty. If so, we cannot remove an element if self.size == 0: return None # if not empty, remove the tail (LIFO) and decrase the size by 1 else: self.size -= 1 return self.storage.remove_tail()
class Stack: def __init__(self): self.size = 0 # Store Data through invocation of the LinkedList self.storage = LinkedList() def __len__(self): # Returning the tracked size of the Linked list return self.size def push(self, value): # Add to size as adding items self.size += 1 # add item to the tail through LinkedList methods return self.storage.add_to_tail(value) def pop(self): # Establish empty size of List if self.storage.head == None: self.size = 0 else: # Subtract as removing items self.size -= 1 return self.storage.remove_tail()