class TwoQueuesStack:
def __init__(self):
self.data = ArrayQueue()
self.helpqueue = ArrayQueue()
def push(self, pushint):
self.data.add(pushint)
def peek(self):
if self.data.isEmpty():
raise RuntimeError("Stack is empty")
while (len(self.data) != 1):
self.helpqueue.add(self.data.poll())
res = self.data.poll()
self.helpqueue.add(res)
swap()
return res
def pop(self):
if self.data.inEmpty():
raise RuntimeError("Stack is empty")
while len(self.data) > 1:
self.helpqueue.add(self.data.poll())
res = self.data.poll()
swap()
return res
def swap():
tmp = self.data
self.data = self.helpqueue
self.helpqueue = tmp
