https://leetcode.com/problems/implement-stack-using-queues/
Implement Stack using Queues - LeetCode
Can you solve this real interview question? Implement Stack using Queues - Implement a last-in-first-out (LIFO) stack using only two queues. The implemented stack should support all the functions of a normal stack (push, top, pop, and empty). Implement the
leetcode.com
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class MyStack:
def __init__(self):
self.q = collections.deque()
def push(self, x: int) -> None:
self.q.append(x)
for i in range(len(self.q)-1):
self.q.append(self.q.popleft())
def pop(self) -> int:
return self.q.popleft()
def top(self) -> int:
return self.q[0]
def empty(self) -> bool:
return len(self.q) == 0
# Your MyStack object will be instantiated and called as such:
# obj = MyStack()
# obj.push(x)
# param_2 = obj.pop()
# param_3 = obj.top()
# param_4 = obj.empty()
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cs |
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