def test_push_one_value():
stack = Stack()
stack.push(5)
actual = stack.top.value
# actual = stack.peek()
expected = 5
assert actual == expected
def sort_stack(stack):
i, j = 0, int(stack.size/2)
size = stack.size
while i < j:
min, max = find_min_max(stack, i)
k = 0
aux = Stack()
while k <= size:
if k == size - i:
aux.push(max)
else:
value = stack.pop()
if value != max:
aux.push(value)
k += 1
k = 0
stack = Stack()
while k <= size:
if k == size - i:
stack.push(min)
else:
value = aux.pop()
if value != min:
stack.push(value)
k += 1
i += 1
return stack
def sort_stack2(stack):
changes = 0
is_max = True
while changes < stack.size - 1 or not is_max:
aux = Stack()
changes = 0
max_min = stack.pop()
while not stack.is_empty():
v = stack.pop()
if (is_max and v > max_min) or (not is_max and v < max_min):
max_min, v = v, max_min
changes += 1
aux.push(v)
aux.push(max_min)
stack = aux
is_max = not is_max
return stack
class QueueStack:
def __init__(self, value):
self.stack = Stack(value)
self.r_stack = Stack(value)
def add(self, value):
self.stack.push(value)
self.flip_stack()
def remove(self):
value = self.r_stack.pop()
self.unflip_stack()
return value
def peek(self):
return self.r_stack.peek()
def is_empty(self):
return self.r_stack.is_empty()
def __str__(self):
return str(self.stack) + ' - ' + str(self.r_stack)
def flip_stack(self):
aux = copy.copy(self.stack) # or use a array to pop the two stacks
self.r_stack = Stack(aux.pop())
while not aux.is_empty():
self.r_stack.push(aux.pop())
def unflip_stack(self):
aux = copy.copy(self.r_stack)
self.stack = Stack(aux.pop())
while not aux.is_empty():
self.stack.push(aux.pop())
def stack_vals():
stack = Stack()
stack.push(10)
stack.push(-2)
stack.push('a')
return stack