def test_LinkedList(self):
linked_list = LinkedList()
self.assertEqual(linked_list.size(), 0)
linked_list_num = LinkedList(Node(1))
self.assertEqual(linked_list_num.pop(), 1)
self.assertEqual(linked_list_num.push(1), None)
self.assertEqual(linked_list_num.head.data, 1)
self.assertEqual(linked_list_num.head.next, None)
self.assertEqual(linked_list_num.push(2), None)
self.assertEqual(linked_list_num.pop(), 2)
self.assertEqual(linked_list_num.size(), 1)
self.assertEqual(linked_list_num.is_empty(), False)
def test_5(self):
""" test pop() """
l = LinkedList()
n1 = Node(5)
n2 = Node(3)
l.append(n1)
l.append(n2)
n = l.pop()
self.assertEqual(n._value, 5)
class StackLinked:
""" A stack data structure implemented with a singly linked list.
Attributes:
capacity(int): The size limiter of the stack.
head(LinkedList): The LinkedList that stores our nodes.
num_items(int): The number of items in the stack.
"""
def __init__(self, capacity):
self.capacity = capacity
self.items = LinkedList()
self.num_items = 0
def __repr__(self):
return "StackLinked({}, {}, {})".format(self.capacity, self.items,
self.num_items)
def __eq__(self, other):
return (isinstance(self, StackLinked) == isinstance(
other, StackLinked) and self.capacity == other.capacity
and self.items == other.items
and self.num_items == other.num_items)
def is_empty(self):
""" Checks if the stack is empty.
Args:
self(StackLinked): The current object referencing this method.
Returns:
boolean: True if the stack is empty, else false.
"""
return self.num_items == 0
def is_full(self):
""" Checks if the stack is full.
Args:
self(StackLinked): The current object referencing this method.
Returns:
boolean: True if the stack is full, else false.
"""
return self.num_items == self.capacity
def push(self, item):
""" Add an item to the stack. If the stack is full return Error.
Args:
self(StackLinked): The current object referencing this method.
item(Any): The data that is going to be pushed to the stack
Returns:
None: Does not return anything
"""
if self.is_full():
raise IndexError
self.items.push(item)
self.num_items += 1
def pop(self):
""" Removes an item from the top of the stack. If the stack is empty
return None.
Args:
self(StackLinked): The current object referencing this method.
Returns:
Any: The data that was removed from the top of the stack.
"""
if self.is_empty():
raise IndexError
self.num_items -= 1
return self.items.pop()
def peek(self):
""" The item at the top of the Stack.
Args:
self(StackLinked): The current object referencing this method.
Returns:
*: The data at the top of the Stack.
"""
return self.items.head.get_data()
def size(self):
""" The size of the StackLinked.
Args:
self(StackLinked): The current object referencing this method.
Returns:
int: Number of items in the Stack.
"""
return self.items.num_items