class Test_myStack(unittest.TestCase):
def setUp(self):
self.testStack = MyStack()
def test_pop_emptyStackCase(self):
with self.assertRaises(StackEmptyException):
self.testStack.pop()
def test_pop_done(self):
self.testStack.push('abc')
self.testStack.push('xyz')
self.testStack.push('123')
self.testStack.pop()
self.assertEqual(self.testStack.data, ['abc', 'xyz'])
def test_peek(self):
with self.assertRaises(StackEmptyException):
self.testStack.peek()
def test_push_typeErrorCase(self):
with self.assertRaises(TypeError):
self.testStack.push(10)
def test_push_done(self):
self.testStack.push('abc')
self.testStack.push('xyz')
self.testStack.push('123')
self.testStack.push('456')
self.assertEqual(self.testStack.data, ['abc', 'xyz', '123', '456'])
def test_contain(self):
self.testStack.push('abc')
self.assertTrue(self.testStack.contains('abc'), 'Must be True')
def next_greater_element(lst):
stack = MyStack()
res = [None] * len(lst)
for i in range(len(lst) - 1, -1, -1):
# iterate backwards
while not stack.is_empty() and stack.peek() <= lst[i]:
stack.pop()
if not stack.is_empty():
# use the top element as nge if available
res[i] = stack.peek()
else:
res[i] = -1
stack.push(lst[i])
return res
def sort_stack(stack):
temp_stack = MyStack()
while not stack.is_empty():
value = stack.pop()
# if value is not none and larger, push it at the top of temp_stack
if temp_stack.peek() is not None and value >= temp_stack.peek():
temp_stack.push(value)
else:
while not temp_stack.is_empty():
stack.push(temp_stack.pop())
# place value as the smallest element in temp_stack
temp_stack.push(value)
# Transfer from temp_stack => stack
while not temp_stack.is_empty():
stack.push(temp_stack.pop())
return stack