class MyQueue:
def __init__(self):
self.new_stack = Stack()
self.old_stack = Stack()
def _shift_stacks(self):
if self.old_stack.is_empty():
while not self.new_stack.is_empty():
self.old_stack.push(self.new_stack.pop())
def add(self, value):
return self.new_stack.push(value)
def peek(self):
if self.is_empty():
return False
self._shift_stacks()
return self.old_stack.peek()
def remove(self):
if self.is_empty():
return False
self._shift_stacks()
return self.old_stack.pop()
def is_empty(self):
return len(self) == 0
def __len__(self):
return len(self.new_stack) + len(self.old_stack)
class SortedStack(Stack):
def __init__(self):
super().__init__()
self.temp_stack = Stack()
def push(self, item):
if self.is_empty() or item < self.peek():
super().push(item)
else:
while self.peek() is not None and item > self.peek():
self.temp_stack.push(self.pop())
super().push(item)
while not self.temp_stack.is_empty():
super().push(self.temp_stack.pop())