class MyStack(object):
def __init__(self):
"""
Initialize your data structure here.
"""
self.input_queue = Queue()
self.output_queue = Queue()
def push(self, x):
"""
Push element x onto stack.
:type x: int
:rtype: None
"""
self.input_queue.push(x)
def pop(self):
"""
Removes the element on top of the stack and returns that element.
:rtype: int
"""
size = self.input_queue.size()
if size == 0:
return None
for i in range(size - 1):
self.output_queue.push((self.input_queue.pop()))
item = self.input_queue.pop()
self.input_queue, self.output_queue = self.output_queue, self.input_queue
return item
def top(self):
"""
Get the top element.
:rtype: int
"""
size = self.input_queue.size()
if size == 0:
return None
for i in range(size - 1):
self.output_queue.push((self.input_queue.pop()))
item = self.input_queue.peek()
self.output_queue.push((self.input_queue.pop()))
self.input_queue, self.output_queue = self.output_queue, self.input_queue
return item
def empty(self):
"""
Returns whether the stack is empty.
:rtype: bool
"""
return self.input_queue.is_empty()
class TestQueue(unittest.TestCase):
@classmethod
def setUpClass(self):
self.initial_list = [i for i in range(5)]
@classmethod
def tearDownClass(self):
print("All tests for queue completed")
def setUp(self):
# print("Initializing queue")
self.queue = Queue(8, 0, initial_iter=self.initial_list)
def tearDown(self):
pass
def test_head(self):
"""
Test getting top element
"""
self.assertEqual(4, self.queue.head())
def test_tail(self):
"""
Test getting top element
"""
self.assertEqual(0, self.queue.tail())
def test_enqueue(self):
"""
Test pushing to stack top
"""
self.queue.enqueue(5)
self.assertEqual(5, self.queue.tail())
self.assertNotEqual(5, self.queue.head())
self.assertEqual(4, self.queue.head())
self.assertEqual(6, self.queue.size())
def test_dequeue(self):
"""
Test popping
"""
for x in range(4, -1, -1):
self.assertEqual(x, self.queue.dequeue())
self.assertEqual(0, self.queue.size())