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q0232.py
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q0232.py
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class MyQueue:
push_stack = []
pop_stack = []
count = 0
def __init__(self):
"""
Initialize your data structure here.
"""
self.push_stack = []
self.pop_stack = []
self.count = 0
def push(self, x: int) -> None:
"""
Push element x to the back of queue.
"""
self.push_stack.append(x)
self.count += 1
def pop(self) -> int:
"""
Removes the element from in front of queue and returns that element.
"""
if self.count == 0:
return -1
self.count -= 1
if len(self.pop_stack) == 0:
for _ in range(len(self.push_stack)):
self.pop_stack.append(self.push_stack.pop())
return self.pop_stack.pop()
def peek(self) -> int:
"""
Get the front element.
"""
if self.count == 0:
return -1
if len(self.pop_stack) == 0:
for _ in range(len(self.push_stack)):
self.pop_stack.append(self.push_stack.pop())
return self.pop_stack[-1]
def empty(self) -> bool:
"""
Returns whether the queue is empty.
"""
return self.count == 0
# Your MyQueue object will be instantiated and called as such:
# obj = MyQueue()
# obj.push(1)
# obj.push(2)
# param_2 = obj.pop()
# param_3 = obj.peek()
# param_4 = obj.empty()