Leetcode 232用栈实现队列

232用栈实现队列

class MyQueue:

    def __init__(self):
        """
        Initialize your data structure here.
        """
        self.items = []


    def push(self, x: int) -> None:
        """
        Push element x to the back of queue.
        """
        self.items.append(x)


    def pop(self) -> int:
        """
        Removes the element from in front of queue and returns that element.
        """
        new_items = self.items[::-1]
        pop_item = new_items.pop()
        self.items = new_items[::-1]
        return pop_item


    def peek(self) -> int:
        """
        Get the front element.
        """
        new_items = self.items[::-1]
        peek_item = new_items[-1]
        self.items = new_items[::-1]
        return peek_item


    def empty(self) -> bool:
        """
        Returns whether the queue is empty.
        """
        return self.items == []