225. Implement Stack using Queues

https://leetcode.com/problems/implement-stack-using-queues/

Python

from collections import deque


class MyStack:

    def __init__(self):
        self.queue = deque()
        self.head = None

    def push(self, x: int) -> None:
        self.queue.append(x)
        self.head = x

    def pop(self) -> int:
        temp = deque()
        while len(self.queue) > 1:
            x = self.queue.popleft()
            temp.append(x)
            self.head = x

        ans = self.queue.popleft()

        self.queue = temp

        return ans

    def top(self) -> int:
        return self.head

    def empty(self) -> bool:
        return not bool(self.queue)