def sort_stack(s: Stack):
buffer = Stack()
while s:
cur = s.pop()
while buffer and buffer.peek() > cur:
s.push(buffer.pop())
buffer.push(cur)
while buffer:
s.push(buffer.pop())
class SortedStack:
def __init__(self):
self._main = Stack()
self._buffer = Stack()
@staticmethod
def _move_from_to(s1, s2):
while s1:
s2.push(s1.pop())
def _to_main(self):
self._move_from_to(self._buffer, self._main)
def _to_buffer(self):
self._move_from_to(self._main, self._buffer)
def push(self, val):
""" insert 2
_main: [7, 5, 3] """
self._to_buffer()
while self._buffer:
cur = self._buffer.pop()
if val >= cur:
self._buffer.push(cur)
self._buffer.push(val)
break
self._main.push(cur)
else:
self._buffer.push(val)
self._to_main()
def pop(self):
self._to_main()
return self._main.pop()
def peek(self):
self._to_main()
return self._main.peek()
def __bool__(self):
return bool(self._main or self._buffer)
class Queue:
def __init__(self):
self.back = Stack()
self.front = Stack()
@staticmethod
def _move_from_to(s1: Stack, s2: Stack):
while s1:
s2.push(s1.pop())
def add(self, val):
self._move_from_to(self.front, self.back)
self.back.push(val)
def remove(self):
self._move_from_to(self.back, self.front)
return self.front.pop()
def peek(self):
self._move_from_to(self.back, self.front)
return self.front.peek()