Letter Queue

Letter Queue


在计算机科学中,队列是一种特殊的数据类型,其中集合中的实体按顺序排列,对集合的主要操作是将实体添加到后端位置(enqueue 或 push),以及将实体从前端位置移除(dequeue 或 pop)。这使得队列成为一种先进先出(FIFO)数据结构。在先进先出数据结构中,第一个加入队列的元素将是第一个被移除的元素。这相当于要求一旦添加了一个新元素,就必须先移除之前添加的所有元素,然后才能移除新元素。

我们将用 Python 来模拟队列过程。我们将得到一系列命令
- "PUSH X" - enqueueX ,其中X 是一个大写字母。
- "POP" - 如果队列为空,则什么也不做。


["PUSH A", "POP",...

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