class MyQueue:
def __init__(self):
self.stack1 = Stack(0)
self.stack2 = Stack(0)
self.stack1.pop()
self.stack2.pop()
self.use1 = True
def add(self, value):
if self.use1:
self.stack1.push(value)
else:
self.stack2.push(value)
def remove(self):
if self.use1:
self.use1 = not self.use1
while (not self.stack1.isEmpty()):
self.stack2.push(self.stack1.pop())
return self.stack2.pop()
else:
self.use1 = not self.use1
while (not self.stack2.isEmpty()):
self.stack1.push(self.stack2.pop())
return self.stack1.pop()
def parChecker(string):
s=Stack()
balanced=True
index=0
while index<len(string) and balanced:
symbol=string[index]
if symbol in "([{":
s.push(symbol)
else:
if s.isEmpty():
balanced=False
else:
top=s.pop()
## we have to see the top that we have removed matches the symbol
if not matches(top,symbol):
balanced=False
index+=1
if balanced and s.isEmpty():
return True
else:
return False